SEC Info - Opti-Harvest, Inc. - ‘S-1’ on 8/31/22

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Opti-Harvest, Inc. – ‘S-1’ on 8/31/22 – ‘EX-101.LAB’

On: Wednesday, 8/31/22, at 5:09pm ET · Accession #: 1493152-22-24661 · File #: 333-267203

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 8/31/22  Opti-Harvest, Inc.                S-1                   93:49M                                    M2 Compliance LLC/FA

Registration Statement (General Form) — Form S-1 — SA’33

Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: S-1         Registration Statement (General Form)               HTML   2.75M 
 2: EX-1.1      Underwriting Agreement or Conflict Minerals Report  HTML    438K 
 3: EX-3.1.1    Articles of Incorporation/Organization or Bylaws    HTML     23K 
 4: EX-3.1.2    Articles of Incorporation/Organization or Bylaws    HTML     23K 
 5: EX-3.1.3    Articles of Incorporation/Organization or Bylaws    HTML     24K 
 6: EX-3.1.4    Articles of Incorporation/Organization or Bylaws    HTML     23K 
 7: EX-3.2      Articles of Incorporation/Organization or Bylaws    HTML     32K 
 8: EX-4.1      Instrument Defining the Rights of Security Holders  HTML     22K 
 9: EX-4.2      Instrument Defining the Rights of Security Holders  HTML    135K 
10: EX-4.3      Instrument Defining the Rights of Security Holders  HTML    268K 
11: EX-4.4      Instrument Defining the Rights of Security Holders  HTML     31K 
12: EX-4.6      Instrument Defining the Rights of Security Holders  HTML    261K 
13: EX-5.1      Opinion of Counsel re: Legality                     HTML     38K 
14: EX-5.2      Opinion of Counsel re: Legality                     HTML     24K 
15: EX-10.1     Material Contract                                   HTML     42K 
24: EX-10.10    Material Contract                                   HTML    179K 
25: EX-10.11    Material Contract                                   HTML     33K 
26: EX-10.12    Material Contract                                   HTML     24K 
16: EX-10.2     Material Contract                                   HTML     23K 
17: EX-10.3     Material Contract                                   HTML     25K 
18: EX-10.4     Material Contract                                   HTML     61K 
19: EX-10.5     Material Contract                                   HTML     25K 
20: EX-10.6     Material Contract                                   HTML    120K 
21: EX-10.7     Material Contract                                   HTML    178K 
22: EX-10.8     Material Contract                                   HTML     59K 
23: EX-10.9     Material Contract                                   HTML    660K 
27: EX-14.1     Code of Ethics                                      HTML     66K 
28: EX-23.1     Consent of Expert or Counsel                        HTML     26K 
29: EX-FILING FEES  Calculation of Filing Fee Tables                HTML     40K 
35: R1          Cover                                               HTML     58K 
36: R2          Balance Sheets                                      HTML    112K 
37: R3          Balance Sheets (Parenthetical)                      HTML     47K 
38: R4          Statements of Operations                            HTML     85K 
39: R5          Statements of Changes in Shareholders' Equity       HTML     86K 
                (Deficit)                                                        
40: R6          Statements of Cash Flows                            HTML    124K 
41: R7          Basis of Presentation and Liquidity                 HTML     45K 
42: R8          Significant Accounting Policies                     HTML    118K 
43: R9          Property and Equipment                              HTML     44K 
44: R10         Earnout and Royalty Obligations                     HTML     55K 
45: R11         Senior Convertible Notes Payable and Warrants       HTML     76K 
46: R12         Note Payable                                        HTML     32K 
47: R13         Loans payable                                       HTML     41K 
48: R14         Shareholders? Equity (Deficit)                      HTML    273K 
49: R15         Commitments and Contingencies                       HTML    102K 
50: R16         Income Taxes                                        HTML     44K 
51: R17         Related Party Transactions                          HTML     43K 
52: R18         Subsequent Events                                   HTML     47K 
53: R19         Inventory                                           HTML     31K 
54: R20         Intangible Assets and Contingent Earnout Liability  HTML     54K 
55: R21         Significant Accounting Policies (Policies)          HTML    154K 
56: R22         Significant Accounting Policies (Tables)            HTML     49K 
57: R23         Property and Equipment (Tables)                     HTML     39K 
58: R24         Senior Convertible Notes Payable and Warrants       HTML     35K 
                (Tables)                                                         
59: R25         Loans payable (Tables)                              HTML     31K 
60: R26         Shareholders? Equity (Deficit) (Tables)             HTML    123K 
61: R27         Income Taxes (Tables)                               HTML     38K 
62: R28         Inventory (Tables)                                  HTML     30K 
63: R29         Basis of Presentation and Liquidity (Details        HTML     51K 
                Narrative)                                                       
64: R30         Schedule of Estimated Useful Lives of Property and  HTML     35K 
                Equipment (Details)                                              
65: R31         Schedule of Anti-Dilutive Securities of Earning     HTML     40K 
                Per Share (Details)                                              
66: R32         Significant Accounting Policies (Details            HTML     48K 
                Narrative)                                                       
67: R33         Schedule of Property and Equipment (Details)        HTML     41K 
68: R34         Property and Equipment (Details Narrative)          HTML     34K 
69: R35         Earnout and Royalty Obligations (Details            HTML     70K 
                Narrative)                                                       
70: R36         Schedule of Senior Convertible Notes Payable        HTML     33K 
                (Details)                                                        
71: R37         Senior Convertible Notes Payable and Warrants       HTML    144K 
                (Details Narrative)                                              
72: R38         Note Payable (Details Narrative)                    HTML     34K 
73: R39         Loans payable (Details Narrative)                   HTML     54K 
74: R40         Summary of Warrants (Details)                       HTML     50K 
75: R41         Summary of Outstanding Warrants Exercise Price      HTML     50K 
                (Details)                                                        
76: R42         Summary of Options (Details)                        HTML     49K 
77: R43         Summary of Outstanding Options Exercise Price       HTML     44K 
                (Details)                                                        
78: R44         Shareholders? Equity (Deficit) (Details Narrative)  HTML    487K 
79: R45         Commitments and Contingencies (Details Narrative)   HTML    199K 
80: R46         Schedule of Effective Income Tax Rate (Details)     HTML     34K 
81: R47         Schedule of Components of Deferred Taxes (Details)  HTML     30K 
82: R48         Income Taxes (Details Narrative)                    HTML     31K 
83: R49         Related Party Transactions (Details Narrative)      HTML     65K 
84: R50         Subsequent Events (Details Narrative)               HTML    103K 
85: R51         Schedule of Inventory (Details)                     HTML     31K 
86: R52         Inventory (Details Narrative)                       HTML     26K 
87: R53         Schedule of Loans Payable (Details)                 HTML     30K 
88: R54         Intangible Assets and Contingent Earnout Liability  HTML     73K 
                (Details Narrative)                                              
91: XML         IDEA XML File -- Filing Summary                      XML    134K 
89: XML         XBRL Instance -- forms-1_htm                         XML   1.82M 
90: EXCEL       IDEA Workbook of Financial Reports                  XLSX    176K 
31: EX-101.CAL  Inline XBRL Taxonomy Extension Calculation           XML    147K 
                Linkbase Document -- opti-20220630_cal                           
32: EX-101.DEF  Inline XBRL Taxonomy Extension Definition Linkbase   XML    847K 
                Document -- opti-20220630_def                                    
33: EX-101.LAB  Inline XBRL Taxonomy Extension Label Linkbase        XML   1.15M 
                Document -- opti-20220630_lab                                    
34: EX-101.PRE  Inline XBRL Taxonomy Extension Presentation          XML    975K 
                Linkbase Document -- opti-20220630_pre                           
30: EX-101.SCH  Inline XBRL Taxonomy Extension Schema Document --    XSD    162K 
                opti-20220630                                                    
92: JSON        XBRL Instance as JSON Data -- MetaLinks              374±   537K 
93: ZIP         XBRL Zipped Folder -- 0001493152-22-024661-xbrl      Zip   1.95M

‘EX-101.LAB’ — Inline XBRL Taxonomy Extension Label Linkbase Document — opti-20220630_lab

This Exhibit is an XBRL XML File.

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<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SeriesAPreferredStockMember_lbl" xml:lang="en-US"> Series A Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_StatementEquityComponentsAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xml:lang="en-US"> Equity Components [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockMember_lbl" xml:lang="en-US"> Common Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockMember" xlink:label="us-gaap_PreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockMember" xlink:to="us-gaap_PreferredStockMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockMember_lbl" xml:lang="en-US"> Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalMember" xlink:to="us-gaap_AdditionalPaidInCapitalMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xml:lang="en-US"> Additional Paid-in Capital [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsMember" xlink:to="us-gaap_RetainedEarningsMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsMember_lbl" xml:lang="en-US"> Retained Earnings [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="us-gaap_SubsequentEventTypeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xml:lang="en-US"> Subsequent Event Type [Axis] </link:label>

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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventMember" xlink:to="us-gaap_SubsequentEventMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventMember_lbl" xml:lang="en-US"> Subsequent Event [Member] </link:label>

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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xml:lang="en-US"> Long-Lived Tangible Asset [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ToolsDiesAndMoldsMember" xlink:label="us-gaap_ToolsDiesAndMoldsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ToolsDiesAndMoldsMember" xlink:to="us-gaap_ToolsDiesAndMoldsMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ToolsDiesAndMoldsMember_lbl" xml:lang="en-US"> Tools, Dies and Molds [Member] </link:label>

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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeAxis" xlink:to="srt_RangeAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_RangeAxis_lbl" xml:lang="en-US"> Statistical Measurement [Axis] </link:label>

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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_MinimumMember_lbl" xml:lang="en-US"> Minimum [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_MaximumMember_lbl" xml:lang="en-US"> Maximum [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VehiclesMember" xlink:label="us-gaap_VehiclesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VehiclesMember" xlink:to="us-gaap_VehiclesMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_VehiclesMember_lbl" xml:lang="en-US"> Vehicles [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OfficeEquipmentMember" xlink:label="us-gaap_OfficeEquipmentMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OfficeEquipmentMember" xlink:to="us-gaap_OfficeEquipmentMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OfficeEquipmentMember_lbl" xml:lang="en-US"> Office Equipment [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>

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<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xml:lang="en-US"> Antidilutive Securities [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantMember" xlink:to="us-gaap_WarrantMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WarrantMember_lbl" xml:lang="en-US"> Warrant [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_OptionsMember" xlink:label="OPTI_OptionsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_OptionsMember" xlink:to="OPTI_OptionsMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_OptionsMember_lbl" xml:lang="en-US"> Options [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_SeniorConvertibleNotesMember" xlink:label="OPTI_SeniorConvertibleNotesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_SeniorConvertibleNotesMember" xlink:to="OPTI_SeniorConvertibleNotesMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_SeniorConvertibleNotesMember_lbl" xml:lang="en-US"> Senior Convertible Notes [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_RestrictedStockUnitsMember" xlink:label="OPTI_RestrictedStockUnitsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_RestrictedStockUnitsMember" xlink:to="OPTI_RestrictedStockUnitsMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_RestrictedStockUnitsMember_lbl" xml:lang="en-US"> Restricted Stock Units [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MajorCustomersAxis" xlink:label="srt_MajorCustomersAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MajorCustomersAxis" xlink:to="srt_MajorCustomersAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_MajorCustomersAxis_lbl" xml:lang="en-US"> Customer [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_OneCustomerMember" xlink:label="OPTI_OneCustomerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_OneCustomerMember" xlink:to="OPTI_OneCustomerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_OneCustomerMember_lbl" xml:lang="en-US"> One Customer [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="us-gaap_ConcentrationRiskByTypeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskByTypeAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskByTypeAxis_lbl" xml:lang="en-US"> Concentration Risk Type [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="us-gaap_CustomerConcentrationRiskMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CustomerConcentrationRiskMember" xlink:to="us-gaap_CustomerConcentrationRiskMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CustomerConcentrationRiskMember_lbl" xml:lang="en-US"> Customer Concentration Risk [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xml:lang="en-US"> Concentration Risk Benchmark [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerMember" xlink:label="us-gaap_RevenueFromContractWithCustomerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerMember" xlink:to="us-gaap_RevenueFromContractWithCustomerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueFromContractWithCustomerMember_lbl" xml:lang="en-US"> Revenue from Contract with Customer Benchmark [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_TwoCustomerMember" xlink:label="OPTI_TwoCustomerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_TwoCustomerMember" xlink:to="OPTI_TwoCustomerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_TwoCustomerMember_lbl" xml:lang="en-US"> Two Customer [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ThreeCustomerMember" xlink:label="OPTI_ThreeCustomerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ThreeCustomerMember" xlink:to="OPTI_ThreeCustomerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ThreeCustomerMember_lbl" xml:lang="en-US"> Three Customer [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_FourCustomerMember" xlink:label="OPTI_FourCustomerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FourCustomerMember" xlink:to="OPTI_FourCustomerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_FourCustomerMember_lbl" xml:lang="en-US"> Four Customer [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_FiveCustomerMember" xlink:label="OPTI_FiveCustomerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FiveCustomerMember" xlink:to="OPTI_FiveCustomerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_FiveCustomerMember_lbl" xml:lang="en-US"> Five Customer [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_NoCustomerMember" xlink:label="OPTI_NoCustomerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_NoCustomerMember" xlink:to="OPTI_NoCustomerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_NoCustomerMember_lbl" xml:lang="en-US"> No Customer [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ComputerEquipmentMember" xlink:label="us-gaap_ComputerEquipmentMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComputerEquipmentMember" xlink:to="us-gaap_ComputerEquipmentMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ComputerEquipmentMember_lbl" xml:lang="en-US"> Computer Equipment [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xml:lang="en-US"> Long-Term Debt, Type [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LoansPayableMember" xlink:label="us-gaap_LoansPayableMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayableMember" xlink:to="us-gaap_LoansPayableMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansPayableMember_lbl" xml:lang="en-US"> Loans Payable [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xml:lang="en-US"> Business Acquisition [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_DisperSolarLLCMember" xlink:label="OPTI_DisperSolarLLCMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DisperSolarLLCMember" xlink:to="OPTI_DisperSolarLLCMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_DisperSolarLLCMember_lbl" xml:lang="en-US"> DisperSolar LLC [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_StatementScenarioAxis" xlink:label="srt_StatementScenarioAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_StatementScenarioAxis" xlink:to="srt_StatementScenarioAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_StatementScenarioAxis_lbl" xml:lang="en-US"> Scenario [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_EarnoutPaymentsMember" xlink:label="OPTI_EarnoutPaymentsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EarnoutPaymentsMember" xlink:to="OPTI_EarnoutPaymentsMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_EarnoutPaymentsMember_lbl" xml:lang="en-US"> Earnout Payments [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductOrServiceAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ProductOrServiceAxis_lbl" xml:lang="en-US"> Product and Service [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LicenseMember" xlink:label="us-gaap_LicenseMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LicenseMember" xlink:to="us-gaap_LicenseMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LicenseMember_lbl" xml:lang="en-US"> License [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProductMember" xlink:label="us-gaap_ProductMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductMember" xlink:to="us-gaap_ProductMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductMember_lbl" xml:lang="en-US"> Product [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_TitleOfIndividualAxis" xlink:label="srt_TitleOfIndividualAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_TitleOfIndividualAxis" xlink:to="srt_TitleOfIndividualAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_TitleOfIndividualAxis_lbl" xml:lang="en-US"> Title of Individual [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_MrBoothMember" xlink:label="OPTI_MrBoothMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrBoothMember" xlink:to="OPTI_MrBoothMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_MrBoothMember_lbl" xml:lang="en-US"> Mr. Booth [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeniorNotesMember" xlink:label="us-gaap_SeniorNotesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeniorNotesMember" xlink:to="us-gaap_SeniorNotesMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SeniorNotesMember_lbl" xml:lang="en-US"> Senior Notes [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_SeniorConvertiblePromissoryNotesMember" xlink:label="OPTI_SeniorConvertiblePromissoryNotesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_SeniorConvertiblePromissoryNotesMember" xlink:to="OPTI_SeniorConvertiblePromissoryNotesMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_SeniorConvertiblePromissoryNotesMember_lbl" xml:lang="en-US"> Senior Convertible Promissory Notes [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xml:lang="en-US"> Sale of Stock [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IPOMember" xlink:to="us-gaap_IPOMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IPOMember_lbl" xml:lang="en-US"> IPO [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xml:lang="en-US"> Debt Instrument [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ConvertiblePromissoryNotesMember" xlink:label="OPTI_ConvertiblePromissoryNotesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ConvertiblePromissoryNotesMember" xlink:to="OPTI_ConvertiblePromissoryNotesMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ConvertiblePromissoryNotesMember_lbl" xml:lang="en-US"> Convertible Promissory Notes [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MeasurementInputTypeAxis" xlink:label="us-gaap_MeasurementInputTypeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputTypeAxis" xlink:to="us-gaap_MeasurementInputTypeAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MeasurementInputTypeAxis_lbl" xml:lang="en-US"> Measurement Input Type [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MeasurementInputCommodityMarketPriceMember" xlink:label="us-gaap_MeasurementInputCommodityMarketPriceMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputCommodityMarketPriceMember" xlink:to="us-gaap_MeasurementInputCommodityMarketPriceMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MeasurementInputCommodityMarketPriceMember_lbl" xml:lang="en-US"> Measurement Input, Commodity Market Price [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MeasurementInputPriceVolatilityMember" xlink:label="us-gaap_MeasurementInputPriceVolatilityMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputPriceVolatilityMember" xlink:to="us-gaap_MeasurementInputPriceVolatilityMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MeasurementInputPriceVolatilityMember_lbl" xml:lang="en-US"> Measurement Input, Price Volatility [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MeasurementInputExpectedDividendRateMember" xlink:label="us-gaap_MeasurementInputExpectedDividendRateMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputExpectedDividendRateMember" xlink:to="us-gaap_MeasurementInputExpectedDividendRateMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MeasurementInputExpectedDividendRateMember_lbl" xml:lang="en-US"> Measurement Input, Expected Dividend Rate [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MeasurementInputRiskFreeInterestRateMember" xlink:label="us-gaap_MeasurementInputRiskFreeInterestRateMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputRiskFreeInterestRateMember" xlink:to="us-gaap_MeasurementInputRiskFreeInterestRateMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MeasurementInputRiskFreeInterestRateMember_lbl" xml:lang="en-US"> Measurement Input, Risk Free Interest Rate [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="us-gaap_RelatedPartyTransactionAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionAxis" xlink:to="us-gaap_RelatedPartyTransactionAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionAxis_lbl" xml:lang="en-US"> Related Party Transaction [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_SeniorConvertibleNoteHoldersMember" xlink:label="OPTI_SeniorConvertibleNoteHoldersMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_SeniorConvertibleNoteHoldersMember" xlink:to="OPTI_SeniorConvertibleNoteHoldersMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_SeniorConvertibleNoteHoldersMember_lbl" xml:lang="en-US"> Senior Convertible Note Holders [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_WarrantHolderMember" xlink:label="OPTI_WarrantHolderMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_WarrantHolderMember" xlink:to="OPTI_WarrantHolderMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_WarrantHolderMember_lbl" xml:lang="en-US"> Warrant Holder [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NotesPayableToBanksMember" xlink:label="us-gaap_NotesPayableToBanksMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayableToBanksMember" xlink:to="us-gaap_NotesPayableToBanksMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotesPayableToBanksMember_lbl" xml:lang="en-US"> Notes Payable to Banks [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PaycheckProtectionProgramLoanMember" xlink:label="OPTI_PaycheckProtectionProgramLoanMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PaycheckProtectionProgramLoanMember" xlink:to="OPTI_PaycheckProtectionProgramLoanMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PaycheckProtectionProgramLoanMember_lbl" xml:lang="en-US"> Paycheck Protection Program Loan [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_lbl" xml:lang="en-US"> Class of Financing Receivable [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AutomobileLoanMember" xlink:label="us-gaap_AutomobileLoanMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AutomobileLoanMember" xlink:to="us-gaap_AutomobileLoanMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AutomobileLoanMember_lbl" xml:lang="en-US"> Automobile Loan [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_SeriesAPreferredStocksMember" xlink:label="OPTI_SeriesAPreferredStocksMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_SeriesAPreferredStocksMember" xlink:to="OPTI_SeriesAPreferredStocksMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_SeriesAPreferredStocksMember_lbl" xml:lang="en-US"> Series A Preferred Stocks [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PrivatePlacementMember" xlink:label="us-gaap_PrivatePlacementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrivatePlacementMember" xlink:to="us-gaap_PrivatePlacementMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrivatePlacementMember_lbl" xml:lang="en-US"> Private Placement [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ConsultantsMember" xlink:label="OPTI_ConsultantsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ConsultantsMember" xlink:to="OPTI_ConsultantsMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ConsultantsMember_lbl" xml:lang="en-US"> Consultants [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xml:lang="en-US"> Related Party [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_TypeOfArrangementAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TypeOfArrangementAxis_lbl" xml:lang="en-US"> Collaborative Arrangement and Arrangement Other than Collaborative [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_AdvisoryBoardAgreementMember" xlink:label="OPTI_AdvisoryBoardAgreementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_AdvisoryBoardAgreementMember" xlink:to="OPTI_AdvisoryBoardAgreementMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_AdvisoryBoardAgreementMember_lbl" xml:lang="en-US"> Advisory Board Agreement [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MeasurementInputExpectedTermMember" xlink:label="us-gaap_MeasurementInputExpectedTermMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputExpectedTermMember" xlink:to="us-gaap_MeasurementInputExpectedTermMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MeasurementInputExpectedTermMember_lbl" xml:lang="en-US"> Measurement Input, Expected Term [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MeasurementInputOptionVolatilityMember" xlink:label="us-gaap_MeasurementInputOptionVolatilityMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputOptionVolatilityMember" xlink:to="us-gaap_MeasurementInputOptionVolatilityMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MeasurementInputOptionVolatilityMember_lbl" xml:lang="en-US"> Measurement Input, Option Volatility [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanNameAxis_lbl" xml:lang="en-US"> Plan Name [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_TwoThousandAndSixteenEquityIncentivePlanMember" xlink:label="OPTI_TwoThousandAndSixteenEquityIncentivePlanMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_TwoThousandAndSixteenEquityIncentivePlanMember" xlink:to="OPTI_TwoThousandAndSixteenEquityIncentivePlanMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_TwoThousandAndSixteenEquityIncentivePlanMember_lbl" xml:lang="en-US"> 2016 Equity Incentive Plan [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeInstrumentRiskAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeInstrumentRiskAxis_lbl" xml:lang="en-US"> Derivative Instrument [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockOptionMember" xlink:label="us-gaap_StockOptionMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockOptionMember" xlink:to="us-gaap_StockOptionMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockOptionMember_lbl" xml:lang="en-US"> Equity Option [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ChiefExecutiveOfficerMember" xlink:label="srt_ChiefExecutiveOfficerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ChiefExecutiveOfficerMember" xlink:to="srt_ChiefExecutiveOfficerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ChiefExecutiveOfficerMember_lbl" xml:lang="en-US"> Chief Executive Officer [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ChiefFinancialOfficerMember" xlink:label="srt_ChiefFinancialOfficerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ChiefFinancialOfficerMember" xlink:to="srt_ChiefFinancialOfficerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ChiefFinancialOfficerMember_lbl" xml:lang="en-US"> Chief Financial Officer [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OfficerMember" xlink:label="srt_OfficerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_OfficerMember" xlink:to="srt_OfficerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_OfficerMember_lbl" xml:lang="en-US"> Officer [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_TwoThousandSixteenStockIncentivePlanMember" xlink:label="OPTI_TwoThousandSixteenStockIncentivePlanMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_TwoThousandSixteenStockIncentivePlanMember" xlink:to="OPTI_TwoThousandSixteenStockIncentivePlanMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_TwoThousandSixteenStockIncentivePlanMember_lbl" xml:lang="en-US"> 2016 Stock Incentive Plan [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockMember" xlink:label="us-gaap_EmployeeStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeStockMember" xlink:to="us-gaap_EmployeeStockMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeStockMember_lbl" xml:lang="en-US"> Employee Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_LegalEntityAxis" xlink:label="dei_LegalEntityAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LegalEntityAxis" xlink:to="dei_LegalEntityAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_LegalEntityAxis_lbl" xml:lang="en-US"> Legal Entity [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_KingdomBuildingIncMember" xlink:label="OPTI_KingdomBuildingIncMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_KingdomBuildingIncMember" xlink:to="OPTI_KingdomBuildingIncMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_KingdomBuildingIncMember_lbl" xml:lang="en-US"> Kingdom Building Inc [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_TerminationAgreementMember" xlink:label="OPTI_TerminationAgreementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_TerminationAgreementMember" xlink:to="OPTI_TerminationAgreementMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_TerminationAgreementMember_lbl" xml:lang="en-US"> Termination Agreement [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_AwardTypeAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AwardTypeAxis_lbl" xml:lang="en-US"> Award Type [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockUnitsRSUMember" xlink:to="us-gaap_RestrictedStockUnitsRSUMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xml:lang="en-US"> Restricted Stock Units (RSUs) [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_TwoThousandTwentyTwoStockIncentivePlanMember" xlink:label="OPTI_TwoThousandTwentyTwoStockIncentivePlanMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_TwoThousandTwentyTwoStockIncentivePlanMember" xlink:to="OPTI_TwoThousandTwentyTwoStockIncentivePlanMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_TwoThousandTwentyTwoStockIncentivePlanMember_lbl" xml:lang="en-US"> 2022 Stock Incentive Plan [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredCompensationShareBasedPaymentsMember" xlink:label="us-gaap_DeferredCompensationShareBasedPaymentsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredCompensationShareBasedPaymentsMember" xlink:to="us-gaap_DeferredCompensationShareBasedPaymentsMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredCompensationShareBasedPaymentsMember_lbl" xml:lang="en-US"> Deferred Compensation, Share-Based Payments [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_EmployementAgreementMember" xlink:label="OPTI_EmployementAgreementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EmployementAgreementMember" xlink:to="OPTI_EmployementAgreementMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_EmployementAgreementMember_lbl" xml:lang="en-US"> Employement Agreement [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_MrHandysMember" xlink:label="OPTI_MrHandysMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrHandysMember" xlink:to="OPTI_MrHandysMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_MrHandysMember_lbl" xml:lang="en-US"> Mr. Handys [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_StockIncentivePlanMember" xlink:label="OPTI_StockIncentivePlanMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_StockIncentivePlanMember" xlink:to="OPTI_StockIncentivePlanMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_StockIncentivePlanMember_lbl" xml:lang="en-US"> Stock Incentive Plan [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:label="us-gaap_ClassOfWarrantOrRightAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightAxis_lbl" xml:lang="en-US"> Class of Warrant or Right [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_WarrantExercisePriceOneMember" xlink:label="OPTI_WarrantExercisePriceOneMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_WarrantExercisePriceOneMember" xlink:to="OPTI_WarrantExercisePriceOneMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_WarrantExercisePriceOneMember_lbl" xml:lang="en-US"> Warrant Exercise Price One [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_WarrantExercisePriceTwoMember" xlink:label="OPTI_WarrantExercisePriceTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_WarrantExercisePriceTwoMember" xlink:to="OPTI_WarrantExercisePriceTwoMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_WarrantExercisePriceTwoMember_lbl" xml:lang="en-US"> Warrant Exercise Price Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_WarrantExercisePriceThreeMember" xlink:label="OPTI_WarrantExercisePriceThreeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_WarrantExercisePriceThreeMember" xlink:to="OPTI_WarrantExercisePriceThreeMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_WarrantExercisePriceThreeMember_lbl" xml:lang="en-US"> Warrant Exercise Price Three [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_WarrantExercisePriceFourMember" xlink:label="OPTI_WarrantExercisePriceFourMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_WarrantExercisePriceFourMember" xlink:to="OPTI_WarrantExercisePriceFourMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_WarrantExercisePriceFourMember_lbl" xml:lang="en-US"> Warrant Exercise Price Four [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_lbl" xml:lang="en-US"> Exercise Price Range [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ExercisePriceOneMember" xlink:label="OPTI_ExercisePriceOneMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ExercisePriceOneMember" xlink:to="OPTI_ExercisePriceOneMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ExercisePriceOneMember_lbl" xml:lang="en-US"> Exercise Price One [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_KingdomBuildingConsultingAgreementMember" xlink:label="OPTI_KingdomBuildingConsultingAgreementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_KingdomBuildingConsultingAgreementMember" xlink:to="OPTI_KingdomBuildingConsultingAgreementMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_KingdomBuildingConsultingAgreementMember_lbl" xml:lang="en-US"> Kingdom Building Consulting Agreement [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InvestorMember" xlink:label="us-gaap_InvestorMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestorMember" xlink:to="us-gaap_InvestorMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestorMember_lbl" xml:lang="en-US"> Investor [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ConsultingAgreementMember" xlink:label="OPTI_ConsultingAgreementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ConsultingAgreementMember" xlink:to="OPTI_ConsultingAgreementMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ConsultingAgreementMember_lbl" xml:lang="en-US"> Consulting Agreement [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ScenarioForecastMember" xlink:label="srt_ScenarioForecastMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioForecastMember" xlink:to="srt_ScenarioForecastMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ScenarioForecastMember_lbl" xml:lang="en-US"> Forecast [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_INTESecuritiesLLCMember" xlink:label="OPTI_INTESecuritiesLLCMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_INTESecuritiesLLCMember" xlink:to="OPTI_INTESecuritiesLLCMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_INTESecuritiesLLCMember_lbl" xml:lang="en-US"> INTE Securities LLC [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_MrDestlerMember" xlink:label="OPTI_MrDestlerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrDestlerMember" xlink:to="OPTI_MrDestlerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_MrDestlerMember_lbl" xml:lang="en-US"> Mr. Destler [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_EmploymentAgreementMember" xlink:label="OPTI_EmploymentAgreementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EmploymentAgreementMember" xlink:to="OPTI_EmploymentAgreementMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_EmploymentAgreementMember_lbl" xml:lang="en-US"> Employment Agreement [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_EquityIncentivePlanMember" xlink:label="OPTI_EquityIncentivePlanMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EquityIncentivePlanMember" xlink:to="OPTI_EquityIncentivePlanMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_EquityIncentivePlanMember_lbl" xml:lang="en-US"> Equity Incentive Plan [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VestingAxis" xlink:label="us-gaap_VestingAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VestingAxis" xlink:to="us-gaap_VestingAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_VestingAxis_lbl" xml:lang="en-US"> Vesting [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:to="us-gaap_ShareBasedCompensationAwardTrancheOneMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember_lbl" xml:lang="en-US"> Share-Based Payment Arrangement, Tranche One [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:to="us-gaap_ShareBasedCompensationAwardTrancheTwoMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheTwoMember_lbl" xml:lang="en-US"> Share-Based Payment Arrangement, Tranche Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheThreeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:to="us-gaap_ShareBasedCompensationAwardTrancheThreeMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheThreeMember_lbl" xml:lang="en-US"> Share-Based Payment Arrangement, Tranche Three [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationAwardTrancheFourMember" xlink:label="OPTI_ShareBasedCompensationAwardTrancheFourMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationAwardTrancheFourMember" xlink:to="OPTI_ShareBasedCompensationAwardTrancheFourMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ShareBasedCompensationAwardTrancheFourMember_lbl" xml:lang="en-US"> Share Based Compensation Award Tranche Four [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RestatementAxis" xlink:label="srt_RestatementAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RestatementAxis" xlink:to="srt_RestatementAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_RestatementAxis_lbl" xml:lang="en-US"> Revision of Prior Period [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ScenarioPreviouslyReportedMember" xlink:label="srt_ScenarioPreviouslyReportedMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioPreviouslyReportedMember" xlink:to="srt_ScenarioPreviouslyReportedMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ScenarioPreviouslyReportedMember_lbl" xml:lang="en-US"> Previously Reported [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RestatementAdjustmentMember" xlink:label="srt_RestatementAdjustmentMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RestatementAdjustmentMember" xlink:to="srt_RestatementAdjustmentMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_RestatementAdjustmentMember_lbl" xml:lang="en-US"> Revision of Prior Period, Adjustment [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardDateAxis" xlink:label="us-gaap_AwardDateAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardDateAxis" xlink:to="us-gaap_AwardDateAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AwardDateAxis_lbl" xml:lang="en-US"> Award Date [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_JanuaryOneTwoThousandTwentyTwoMember" xlink:label="OPTI_JanuaryOneTwoThousandTwentyTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_JanuaryOneTwoThousandTwentyTwoMember" xlink:to="OPTI_JanuaryOneTwoThousandTwentyTwoMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_JanuaryOneTwoThousandTwentyTwoMember_lbl" xml:lang="en-US"> January 1, 2022 [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_JulyOneTwoThousandTwentyTwoMember" xlink:label="OPTI_JulyOneTwoThousandTwentyTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_JulyOneTwoThousandTwentyTwoMember" xlink:to="OPTI_JulyOneTwoThousandTwentyTwoMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_JulyOneTwoThousandTwentyTwoMember_lbl" xml:lang="en-US"> July 1, 2022 [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_JanuaryOneTwoThousandTwentyThreeMember" xlink:label="OPTI_JanuaryOneTwoThousandTwentyThreeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_JanuaryOneTwoThousandTwentyThreeMember" xlink:to="OPTI_JanuaryOneTwoThousandTwentyThreeMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_JanuaryOneTwoThousandTwentyThreeMember_lbl" xml:lang="en-US"> January 1, 2023 [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_JulyOneTwoThousandTwentyThreeMember" xlink:label="OPTI_JulyOneTwoThousandTwentyThreeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_JulyOneTwoThousandTwentyThreeMember" xlink:to="OPTI_JulyOneTwoThousandTwentyThreeMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_JulyOneTwoThousandTwentyThreeMember_lbl" xml:lang="en-US"> July 1, 2023 [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:to="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl" xml:lang="en-US"> Investment, Name [Axis] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_InvestorsMember" xlink:label="OPTI_InvestorsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_InvestorsMember" xlink:to="OPTI_InvestorsMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_InvestorsMember_lbl" xml:lang="en-US"> Investors [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_InvestorWarrantsMember" xlink:label="OPTI_InvestorWarrantsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_InvestorWarrantsMember" xlink:to="OPTI_InvestorWarrantsMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_InvestorWarrantsMember_lbl" xml:lang="en-US"> Investor Warrants [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_SharehildersMember" xlink:label="OPTI_SharehildersMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_SharehildersMember" xlink:to="OPTI_SharehildersMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_SharehildersMember_lbl" xml:lang="en-US"> Sharehilders [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_MrKlausnerMember" xlink:label="OPTI_MrKlausnerMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrKlausnerMember" xlink:to="OPTI_MrKlausnerMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_MrKlausnerMember_lbl" xml:lang="en-US"> Mr Klausner [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_MrHandyMember" xlink:label="OPTI_MrHandyMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrHandyMember" xlink:to="OPTI_MrHandyMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_MrHandyMember_lbl" xml:lang="en-US"> Mr. Handy [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_AaronDanksMember" xlink:label="OPTI_AaronDanksMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_AaronDanksMember" xlink:to="OPTI_AaronDanksMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_AaronDanksMember_lbl" xml:lang="en-US"> Aaron Danks [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_BoardOfDirectorsChairmanMember" xlink:label="srt_BoardOfDirectorsChairmanMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_BoardOfDirectorsChairmanMember" xlink:to="srt_BoardOfDirectorsChairmanMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_BoardOfDirectorsChairmanMember_lbl" xml:lang="en-US"> Board of Directors Chairman [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ConsultantsAgreementMember" xlink:label="OPTI_ConsultantsAgreementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ConsultantsAgreementMember" xlink:to="OPTI_ConsultantsAgreementMember_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ConsultantsAgreementMember_lbl" xml:lang="en-US"> Consultants Agreement [Member] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressesTable" xlink:label="dei_EntityAddressesTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressesTable" xlink:to="dei_EntityAddressesTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressesTable_lbl" xml:lang="en-US"> Entity Addresses [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressesLineItems" xlink:label="dei_EntityAddressesLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressesLineItems" xlink:to="dei_EntityAddressesLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressesLineItems_lbl" xml:lang="en-US"> Entity Addresses [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentType" xlink:label="dei_DocumentType"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentType" xlink:to="dei_DocumentType_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentType_lbl" xml:lang="en-US"> Document Type </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AmendmentFlag_lbl" xml:lang="en-US"> Amendment Flag </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AmendmentDescription" xlink:label="dei_AmendmentDescription"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentDescription" xlink:to="dei_AmendmentDescription_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AmendmentDescription_lbl" xml:lang="en-US"> Amendment Description </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentRegistrationStatement" xlink:label="dei_DocumentRegistrationStatement"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentRegistrationStatement" xlink:to="dei_DocumentRegistrationStatement_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentRegistrationStatement_lbl" xml:lang="en-US"> Document Registration Statement </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentAnnualReport" xlink:label="dei_DocumentAnnualReport"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentAnnualReport" xlink:to="dei_DocumentAnnualReport_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentAnnualReport_lbl" xml:lang="en-US"> Document Annual Report </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentQuarterlyReport" xlink:label="dei_DocumentQuarterlyReport"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentQuarterlyReport" xlink:to="dei_DocumentQuarterlyReport_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentQuarterlyReport_lbl" xml:lang="en-US"> Document Quarterly Report </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentTransitionReport" xlink:to="dei_DocumentTransitionReport_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentTransitionReport_lbl" xml:lang="en-US"> Document Transition Report </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentShellCompanyReport" xlink:label="dei_DocumentShellCompanyReport"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentShellCompanyReport" xlink:to="dei_DocumentShellCompanyReport_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentShellCompanyReport_lbl" xml:lang="en-US"> Document Shell Company Report </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentShellCompanyEventDate" xlink:label="dei_DocumentShellCompanyEventDate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentShellCompanyEventDate" xlink:to="dei_DocumentShellCompanyEventDate_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentShellCompanyEventDate_lbl" xml:lang="en-US"> Document Shell Company Event Date </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentPeriodStartDate" xlink:label="dei_DocumentPeriodStartDate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentPeriodStartDate" xlink:to="dei_DocumentPeriodStartDate_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentPeriodStartDate_lbl" xml:lang="en-US"> Document Period Start Date </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentPeriodEndDate" xlink:to="dei_DocumentPeriodEndDate_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentPeriodEndDate_lbl" xml:lang="en-US"> Document Period End Date </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalPeriodFocus" xlink:to="dei_DocumentFiscalPeriodFocus_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xml:lang="en-US"> Document Fiscal Period Focus </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalYearFocus" xlink:to="dei_DocumentFiscalYearFocus_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalYearFocus_lbl" xml:lang="en-US"> Document Fiscal Year Focus </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CurrentFiscalYearEndDate" xlink:to="dei_CurrentFiscalYearEndDate_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xml:lang="en-US"> Current Fiscal Year End Date </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFileNumber" xlink:to="dei_EntityFileNumber_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityFileNumber_lbl" xml:lang="en-US"> Entity File Number </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityRegistrantName" xlink:to="dei_EntityRegistrantName_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityRegistrantName_lbl" xml:lang="en-US"> Entity Registrant Name </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCentralIndexKey" xlink:to="dei_EntityCentralIndexKey_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCentralIndexKey_lbl" xml:lang="en-US"> Entity Central Index Key </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityPrimarySicNumber" xlink:label="dei_EntityPrimarySicNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityPrimarySicNumber" xlink:to="dei_EntityPrimarySicNumber_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityPrimarySicNumber_lbl" xml:lang="en-US"> Entity Primary SIC Number </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityTaxIdentificationNumber" xlink:to="dei_EntityTaxIdentificationNumber_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xml:lang="en-US"> Entity Tax Identification Number </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityIncorporationStateCountryCode" xlink:to="dei_EntityIncorporationStateCountryCode_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityIncorporationStateCountryCode_lbl" xml:lang="en-US"> Entity Incorporation, State or Country Code </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine1" xlink:to="dei_EntityAddressAddressLine1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressAddressLine1_lbl" xml:lang="en-US"> Entity Address, Address Line One </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressAddressLine2" xlink:label="dei_EntityAddressAddressLine2"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine2" xlink:to="dei_EntityAddressAddressLine2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressAddressLine2_lbl" xml:lang="en-US"> Entity Address, Address Line Two </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressAddressLine3" xlink:label="dei_EntityAddressAddressLine3"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine3" xlink:to="dei_EntityAddressAddressLine3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressAddressLine3_lbl" xml:lang="en-US"> Entity Address, Address Line Three </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressCityOrTown" xlink:to="dei_EntityAddressCityOrTown_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressCityOrTown_lbl" xml:lang="en-US"> Entity Address, City or Town </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressStateOrProvince" xlink:to="dei_EntityAddressStateOrProvince_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressStateOrProvince_lbl" xml:lang="en-US"> Entity Address, State or Province </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressCountry" xlink:label="dei_EntityAddressCountry"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressCountry" xlink:to="dei_EntityAddressCountry_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressCountry_lbl" xml:lang="en-US"> Entity Address, Country </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressPostalZipCode" xlink:to="dei_EntityAddressPostalZipCode_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressPostalZipCode_lbl" xml:lang="en-US"> Entity Address, Postal Zip Code </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_CountryRegion" xlink:label="dei_CountryRegion"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CountryRegion" xlink:to="dei_CountryRegion_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CountryRegion_lbl" xml:lang="en-US"> Country Region </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CityAreaCode" xlink:to="dei_CityAreaCode_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CityAreaCode_lbl" xml:lang="en-US"> City Area Code </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LocalPhoneNumber" xlink:to="dei_LocalPhoneNumber_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_LocalPhoneNumber_lbl" xml:lang="en-US"> Local Phone Number </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_Extension" xlink:label="dei_Extension"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_Extension" xlink:to="dei_Extension_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_Extension_lbl" xml:lang="en-US"> Extension </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_WrittenCommunications" xlink:label="dei_WrittenCommunications"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_WrittenCommunications" xlink:to="dei_WrittenCommunications_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_WrittenCommunications_lbl" xml:lang="en-US"> Written Communications </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_SolicitingMaterial" xlink:label="dei_SolicitingMaterial"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_SolicitingMaterial" xlink:to="dei_SolicitingMaterial_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_SolicitingMaterial_lbl" xml:lang="en-US"> Soliciting Material </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_PreCommencementTenderOffer" xlink:label="dei_PreCommencementTenderOffer"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_PreCommencementTenderOffer" xlink:to="dei_PreCommencementTenderOffer_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_PreCommencementTenderOffer_lbl" xml:lang="en-US"> Pre-commencement Tender Offer </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_PreCommencementIssuerTenderOffer" xlink:label="dei_PreCommencementIssuerTenderOffer"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_PreCommencementIssuerTenderOffer" xlink:to="dei_PreCommencementIssuerTenderOffer_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_PreCommencementIssuerTenderOffer_lbl" xml:lang="en-US"> Pre-commencement Issuer Tender Offer </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_Security12bTitle" xlink:to="dei_Security12bTitle_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_Security12bTitle_lbl" xml:lang="en-US"> Title of 12(b) Security </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_NoTradingSymbolFlag" xlink:label="dei_NoTradingSymbolFlag"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_NoTradingSymbolFlag" xlink:to="dei_NoTradingSymbolFlag_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_NoTradingSymbolFlag_lbl" xml:lang="en-US"> No Trading Symbol Flag </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_TradingSymbol" xlink:to="dei_TradingSymbol_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_TradingSymbol_lbl" xml:lang="en-US"> Trading Symbol </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_SecurityExchangeName" xlink:to="dei_SecurityExchangeName_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_SecurityExchangeName_lbl" xml:lang="en-US"> Security Exchange Name </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_Security12gTitle" xlink:label="dei_Security12gTitle"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_Security12gTitle" xlink:to="dei_Security12gTitle_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_Security12gTitle_lbl" xml:lang="en-US"> Title of 12(g) Security </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_SecurityReportingObligation" xlink:label="dei_SecurityReportingObligation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_SecurityReportingObligation" xlink:to="dei_SecurityReportingObligation_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_SecurityReportingObligation_lbl" xml:lang="en-US"> Security Reporting Obligation </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AnnualInformationForm" xlink:label="dei_AnnualInformationForm"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AnnualInformationForm" xlink:to="dei_AnnualInformationForm_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AnnualInformationForm_lbl" xml:lang="en-US"> Annual Information Form </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AuditedAnnualFinancialStatements" xlink:label="dei_AuditedAnnualFinancialStatements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditedAnnualFinancialStatements" xlink:to="dei_AuditedAnnualFinancialStatements_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AuditedAnnualFinancialStatements_lbl" xml:lang="en-US"> Audited Annual Financial Statements </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="dei_EntityWellKnownSeasonedIssuer"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityWellKnownSeasonedIssuer" xlink:to="dei_EntityWellKnownSeasonedIssuer_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xml:lang="en-US"> Entity Well-known Seasoned Issuer </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityVoluntaryFilers" xlink:label="dei_EntityVoluntaryFilers"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityVoluntaryFilers" xlink:to="dei_EntityVoluntaryFilers_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityVoluntaryFilers_lbl" xml:lang="en-US"> Entity Voluntary Filers </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCurrentReportingStatus" xlink:to="dei_EntityCurrentReportingStatus_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCurrentReportingStatus_lbl" xml:lang="en-US"> Entity Current Reporting Status </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityInteractiveDataCurrent" xlink:to="dei_EntityInteractiveDataCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xml:lang="en-US"> Entity Interactive Data Current </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFilerCategory" xlink:to="dei_EntityFilerCategory_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityFilerCategory_lbl" xml:lang="en-US"> Entity Filer Category </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntitySmallBusiness" xlink:to="dei_EntitySmallBusiness_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntitySmallBusiness_lbl" xml:lang="en-US"> Entity Small Business </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityEmergingGrowthCompany" xlink:to="dei_EntityEmergingGrowthCompany_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xml:lang="en-US"> Entity Emerging Growth Company </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityExTransitionPeriod" xlink:label="dei_EntityExTransitionPeriod"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityExTransitionPeriod" xlink:to="dei_EntityExTransitionPeriod_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityExTransitionPeriod_lbl" xml:lang="en-US"> Elected Not To Use the Extended Transition Period </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentAccountingStandard" xlink:label="dei_DocumentAccountingStandard"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentAccountingStandard" xlink:to="dei_DocumentAccountingStandard_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentAccountingStandard_lbl" xml:lang="en-US"> Document Accounting Standard </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_OtherReportingStandardItemNumber" xlink:label="dei_OtherReportingStandardItemNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_OtherReportingStandardItemNumber" xlink:to="dei_OtherReportingStandardItemNumber_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_OtherReportingStandardItemNumber_lbl" xml:lang="en-US"> Other Reporting Standard Item Number </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityShellCompany" xlink:to="dei_EntityShellCompany_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityShellCompany_lbl" xml:lang="en-US"> Entity Shell Company </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityPublicFloat" xlink:label="dei_EntityPublicFloat"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityPublicFloat" xlink:to="dei_EntityPublicFloat_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityPublicFloat_lbl" xml:lang="en-US"> Entity Public Float </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityBankruptcyProceedingsReportingCurrent" xlink:label="dei_EntityBankruptcyProceedingsReportingCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityBankruptcyProceedingsReportingCurrent" xlink:to="dei_EntityBankruptcyProceedingsReportingCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityBankruptcyProceedingsReportingCurrent_lbl" xml:lang="en-US"> Entity Bankruptcy Proceedings, Reporting Current </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xml:lang="en-US"> Entity Common Stock, Shares Outstanding </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentsIncorporatedByReferenceTextBlock" xlink:label="dei_DocumentsIncorporatedByReferenceTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentsIncorporatedByReferenceTextBlock" xlink:to="dei_DocumentsIncorporatedByReferenceTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentsIncorporatedByReferenceTextBlock_lbl" xml:lang="en-US"> Documents Incorporated by Reference [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_ContactPersonnelName" xlink:label="dei_ContactPersonnelName"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_ContactPersonnelName" xlink:to="dei_ContactPersonnelName_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_ContactPersonnelName_lbl" xml:lang="en-US"> Contact Personnel Name </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xml:lang="en-US"> Statement of Financial Position [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsAbstract_lbl" xml:lang="en-US"> ASSETS </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrentAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xml:lang="en-US"> Current Assets: </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Cash" xlink:label="us-gaap_Cash"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Cash" xlink:to="us-gaap_Cash_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Cash_lbl" xml:lang="en-US"> Cash </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNetCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xml:lang="en-US"> Accounts receivable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InventoryNet" xlink:label="us-gaap_InventoryNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNet" xlink:to="us-gaap_InventoryNet_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryNet_lbl" xml:lang="en-US"> Inventory </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl" xml:lang="en-US"> Prepaid expense and other current assets </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsCurrent_lbl" xml:lang="en-US"> Total Current Assets </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> Property and equipment, net of accumulated depreciation </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DepositsAssetsNoncurrent" xlink:label="us-gaap_DepositsAssetsNoncurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepositsAssetsNoncurrent" xlink:to="us-gaap_DepositsAssetsNoncurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepositsAssetsNoncurrent_lbl" xml:lang="en-US"> Vendor deposits </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_DeferredOfferingCost" xlink:label="OPTI_DeferredOfferingCost"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DeferredOfferingCost" xlink:to="OPTI_DeferredOfferingCost_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_DeferredOfferingCost_lbl" xml:lang="en-US"> Deferred offering costs </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US"> Total Assets </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xml:lang="en-US"> LIABILITIES AND SHAREHOLDERS’ EQUITY (DEFICIT) </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xml:lang="en-US"> Current Liabilities: </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_lbl" xml:lang="en-US"> Accounts payable and accrued expenses </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConvertibleNotesPayableCurrent" xlink:label="us-gaap_ConvertibleNotesPayableCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertibleNotesPayableCurrent" xlink:to="us-gaap_ConvertibleNotesPayableCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConvertibleNotesPayableCurrent_lbl" xml:lang="en-US"> Convertible notes payable, net of debt discount </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LoansPayableCurrent" xlink:label="us-gaap_LoansPayableCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayableCurrent" xlink:to="us-gaap_LoansPayableCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansPayableCurrent_lbl" xml:lang="en-US"> Current portion of loan payable </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PatentPurchaseObligationCurrent" xlink:label="OPTI_PatentPurchaseObligationCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PatentPurchaseObligationCurrent" xlink:to="OPTI_PatentPurchaseObligationCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PatentPurchaseObligationCurrent_lbl" xml:lang="en-US"> Patent purchase obligation </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xml:lang="en-US"> Total Current Liabilities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermLoansPayable" xlink:label="us-gaap_LongTermLoansPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermLoansPayable" xlink:to="us-gaap_LongTermLoansPayable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermLoansPayable_lbl" xml:lang="en-US"> Loan payable, less current portion </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermNotesPayable" xlink:label="us-gaap_LongTermNotesPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermNotesPayable" xlink:to="us-gaap_LongTermNotesPayable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermNotesPayable_lbl" xml:lang="en-US"> Note payable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US"> Total Liabilities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingencies" xlink:to="us-gaap_CommitmentsAndContingencies_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xml:lang="en-US"> Commitments and Contingencies </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xml:lang="en-US"> Shareholders’ Equity (Deficit) </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValue" xlink:to="us-gaap_PreferredStockValue_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockValue_lbl" xml:lang="en-US"> Preferred stock, value </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US"> Common stock, value </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapital" xlink:to="us-gaap_AdditionalPaidInCapital_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xml:lang="en-US"> Additional paid-in-capital </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US"> Accumulated deficit </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Total Shareholders’ Equity (Deficit) </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US"> Total liabilities and Shareholders’ Equity (Deficit) </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementTable_lbl" xml:lang="en-US"> Statement [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementLineItems_lbl" xml:lang="en-US"> Statement [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xml:lang="en-US"> Accumulated depreciation </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnamortizedDiscountCurrent" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscountCurrent" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountCurrent_lbl" xml:lang="en-US"> Debt instrument, unamortized discount, current </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xml:lang="en-US"> Preferred stock, par value </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesAuthorized" xlink:to="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xml:lang="en-US"> Preferred stock, shares authorized </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesIssued" xlink:to="us-gaap_PreferredStockSharesIssued_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesIssued_lbl" xml:lang="en-US"> Preferred stock, shares issued </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesOutstanding" xlink:to="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xml:lang="en-US"> Preferred stock, shares outstanding </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xml:lang="en-US"> Common stock, par value </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xml:lang="en-US"> Common stock, shares authorized </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xml:lang="en-US"> Common stock, shares issued </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US"> Common stock, shares outstanding </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xml:lang="en-US"> Income Statement [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xml:lang="en-US"> Net Sales </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfGoodsAndServicesSold" xlink:to="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xml:lang="en-US"> Cost of goods sold </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GrossProfit" xlink:label="us-gaap_GrossProfit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GrossProfit" xlink:to="us-gaap_GrossProfit_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_GrossProfit_lbl" xml:lang="en-US"> Gross loss </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="us-gaap_OperatingExpensesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpensesAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpensesAbstract_lbl" xml:lang="en-US"> Operating expenses: </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingGeneralAndAdministrativeExpense" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xml:lang="en-US"> Selling, general and administrative expense </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpense" xlink:to="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xml:lang="en-US"> Research and development expense </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfIntangibleAssets" xlink:to="us-gaap_AmortizationOfIntangibleAssets_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US"> Amortization of intangible assets </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingExpenses_lbl" xml:lang="en-US"> Total operating expenses </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US"> Loss from operations </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xml:lang="en-US"> Other income and (expenses) </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestExpense" xlink:label="us-gaap_InterestExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US"> Interest expense </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_GainOnForgivenessOfSbaPppLoan" xlink:label="OPTI_GainOnForgivenessOfSbaPppLoan"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_GainOnForgivenessOfSbaPppLoan" xlink:to="OPTI_GainOnForgivenessOfSbaPppLoan_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_GainOnForgivenessOfSbaPppLoan_lbl" xml:lang="en-US"> Gain on forgiveness of SBA PPP loan </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_FinancingCosts" xlink:label="OPTI_FinancingCosts"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FinancingCosts" xlink:to="OPTI_FinancingCosts_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OPTI_FinancingCosts_lbl" xml:lang="en-US"> Financing costs </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_NonoperatingIncomeExpense_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xml:lang="en-US"> Total other income (expense) </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US"> Net Loss </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasic" xlink:to="us-gaap_EarningsPerShareBasic_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xml:lang="en-US"> Loss per share – basic and diluted </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xml:lang="en-US"> Weighted average number of shares outstanding – basic and diluted </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StockholdersEquity_2_lbl" xml:lang="en-US"> Beginning balance, value </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesOutstanding" xlink:label="us-gaap_SharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesOutstanding" xlink:to="us-gaap_SharesOutstanding_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_SharesOutstanding_lbl" xml:lang="en-US"> Beginning balance, shares </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:to="us-gaap_StockIssuedDuringPeriodValueIssuedForServices_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices_lbl" xml:lang="en-US"> Fair value of common shares issued for services </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:to="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_lbl" xml:lang="en-US"> Fair value of common shares issued for services, shares </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xml:lang="en-US"> Common shares issued in private offerings </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xml:lang="en-US"> Common shares issued in private offerings, shares </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLoss_2_lbl" xml:lang="en-US"> Net Loss </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_AdjustmentsToAdditionalPaidInCapitalVestedOptionsAndWarrantIssuedForService" xlink:label="OPTI_AdjustmentsToAdditionalPaidInCapitalVestedOptionsAndWarrantIssuedForService"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_AdjustmentsToAdditionalPaidInCapitalVestedOptionsAndWarrantIssuedForService" xlink:to="OPTI_AdjustmentsToAdditionalPaidInCapitalVestedOptionsAndWarrantIssuedForService_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_AdjustmentsToAdditionalPaidInCapitalVestedOptionsAndWarrantIssuedForService_lbl" xml:lang="en-US"> Fair value of vested options and warrants issued for services </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued_lbl" xml:lang="en-US"> Fair value of warrants recorded as debt discount </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_StockIssuedDuringPeriodValueCommonSharesAndWarrantsIssuedInPrivateOfferings" xlink:label="OPTI_StockIssuedDuringPeriodValueCommonSharesAndWarrantsIssuedInPrivateOfferings"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_StockIssuedDuringPeriodValueCommonSharesAndWarrantsIssuedInPrivateOfferings" xlink:to="OPTI_StockIssuedDuringPeriodValueCommonSharesAndWarrantsIssuedInPrivateOfferings_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_StockIssuedDuringPeriodValueCommonSharesAndWarrantsIssuedInPrivateOfferings_lbl" xml:lang="en-US"> Common shares and warrants issued in private offerings </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_StockIssuedDuringPeriodSharesCommonSharesAndWarrantsIssuedInPrivateOfferings" xlink:label="OPTI_StockIssuedDuringPeriodSharesCommonSharesAndWarrantsIssuedInPrivateOfferings"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_StockIssuedDuringPeriodSharesCommonSharesAndWarrantsIssuedInPrivateOfferings" xlink:to="OPTI_StockIssuedDuringPeriodSharesCommonSharesAndWarrantsIssuedInPrivateOfferings_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_StockIssuedDuringPeriodSharesCommonSharesAndWarrantsIssuedInPrivateOfferings_lbl" xml:lang="en-US"> Common shares and warrants issued in private offerings, shares </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition_lbl" xml:lang="en-US"> Fair value of vested restricted stock units </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueOther" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueOther" xlink:to="us-gaap_StockIssuedDuringPeriodValueOther_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther_lbl" xml:lang="en-US"> Fair value of common shares issued for financing costs </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesOther" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther_lbl" xml:lang="en-US"> Fair value of common shares issued for financing costs, shares </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xml:lang="en-US"> Common shares issued in the exercise of warrants </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xml:lang="en-US"> Common shares issued in the exercise of warrants, shares </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_lbl" xml:lang="en-US"> Fair value of vested stock options </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StockholdersEquity_3_lbl" xml:lang="en-US"> Ending balance, value </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesOutstanding" xlink:to="us-gaap_SharesOutstanding_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_SharesOutstanding_2_lbl" xml:lang="en-US"> Ending balance, shares </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xml:lang="en-US"> Statement of Cash Flows [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> Cash Flows from Operating Activities </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NetIncomeLoss_3_lbl" xml:lang="en-US"> Net loss </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> Adjustments to reconcile net loss to net cash used in operating activities: </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Depreciation" xlink:label="us-gaap_Depreciation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Depreciation" xlink:to="us-gaap_Depreciation_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Depreciation_lbl" xml:lang="en-US"> Depreciation </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_AmortizationOfIntangibleAsset" xlink:label="OPTI_AmortizationOfIntangibleAsset"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_AmortizationOfIntangibleAsset" xlink:to="OPTI_AmortizationOfIntangibleAsset_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="OPTI_AmortizationOfIntangibleAsset_lbl" xml:lang="en-US"> Amortization of intangible assets </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfDebtDiscountPremium" xlink:label="us-gaap_AmortizationOfDebtDiscountPremium"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfDebtDiscountPremium" xlink:to="us-gaap_AmortizationOfDebtDiscountPremium_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfDebtDiscountPremium_lbl" xml:lang="en-US"> Amortization of debt discount </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FinancingCosts" xlink:to="OPTI_FinancingCosts_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_FinancingCosts_2_lbl" xml:lang="en-US"> Financing costs </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InventoryWriteDown" xlink:label="us-gaap_InventoryWriteDown"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryWriteDown" xlink:to="us-gaap_InventoryWriteDown_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryWriteDown_lbl" xml:lang="en-US"> Change in inventory reserve </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims" xlink:label="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims" xlink:to="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims_lbl" xml:lang="en-US"> Fair value of common stock issued for services </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_FairValueOfVestedOptionsAndWarrants" xlink:label="OPTI_FairValueOfVestedOptionsAndWarrants"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FairValueOfVestedOptionsAndWarrants" xlink:to="OPTI_FairValueOfVestedOptionsAndWarrants_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_FairValueOfVestedOptionsAndWarrants_lbl" xml:lang="en-US"> Fair value of vested options and warrants </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_FairValueOfVestedRestrictedStockUnits" xlink:label="OPTI_FairValueOfVestedRestrictedStockUnits"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FairValueOfVestedRestrictedStockUnits" xlink:to="OPTI_FairValueOfVestedRestrictedStockUnits_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="OPTI_FairValueOfVestedRestrictedStockUnits_lbl" xml:lang="en-US"> Fair value of vested restricted stock units </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OPTI_GainOnForgivenessOfSbaPppLoan_2_lbl" xml:lang="en-US"> Gain on forgiveness of SBA PPP loan </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xml:lang="en-US"> Changes in operating assets and liabilities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xml:lang="en-US"> Accounts receivable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="us-gaap_IncreaseDecreaseInInventories"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInInventories" xlink:to="us-gaap_IncreaseDecreaseInInventories_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInInventories_lbl" xml:lang="en-US"> Inventory </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:to="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_lbl" xml:lang="en-US"> Prepaids and other current assets </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xml:lang="en-US"> Accounts payable and accrued expenses </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US"> Net cash used in operating activities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xml:lang="en-US"> Cash Flows from Investing Activities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xml:lang="en-US"> Purchase of property and equipment </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_DepositsToAcquirePropertyPlantAndEquipment" xlink:label="OPTI_DepositsToAcquirePropertyPlantAndEquipment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DepositsToAcquirePropertyPlantAndEquipment" xlink:to="OPTI_DepositsToAcquirePropertyPlantAndEquipment_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OPTI_DepositsToAcquirePropertyPlantAndEquipment_lbl" xml:lang="en-US"> Deposits on purchase of equipment </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US"> Net cash used in investing activities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xml:lang="en-US"> Cash Flows from Financing Activities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xml:lang="en-US"> Proceeds from sale of common stock </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ProceedsFromExerciseOfWarrants" xlink:label="OPTI_ProceedsFromExerciseOfWarrants"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ProceedsFromExerciseOfWarrants" xlink:to="OPTI_ProceedsFromExerciseOfWarrants_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ProceedsFromExerciseOfWarrants_lbl" xml:lang="en-US"> Proceeds from exercise of warrants </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromConvertibleDebt" xlink:label="us-gaap_ProceedsFromConvertibleDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromConvertibleDebt" xlink:to="us-gaap_ProceedsFromConvertibleDebt_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromConvertibleDebt_lbl" xml:lang="en-US"> Proceeds from convertible notes payable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromNotesPayable" xlink:label="us-gaap_ProceedsFromNotesPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromNotesPayable" xlink:to="us-gaap_ProceedsFromNotesPayable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromNotesPayable_lbl" xml:lang="en-US"> Proceeds from note payable </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_RepaymentsOfDeferredOfferingCosts" xlink:label="OPTI_RepaymentsOfDeferredOfferingCosts"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_RepaymentsOfDeferredOfferingCosts" xlink:to="OPTI_RepaymentsOfDeferredOfferingCosts_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OPTI_RepaymentsOfDeferredOfferingCosts_lbl" xml:lang="en-US"> Deferred offering costs </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RepaymentsOfShortTermDebt" xlink:label="us-gaap_RepaymentsOfShortTermDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfShortTermDebt" xlink:to="us-gaap_RepaymentsOfShortTermDebt_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RepaymentsOfShortTermDebt_lbl" xml:lang="en-US"> Repayment of loans payable </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_RepaymentOfPatentPurchaseObligation" xlink:label="OPTI_RepaymentOfPatentPurchaseObligation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_RepaymentOfPatentPurchaseObligation" xlink:to="OPTI_RepaymentOfPatentPurchaseObligation_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OPTI_RepaymentOfPatentPurchaseObligation_lbl" xml:lang="en-US"> Repayment of patent purchase obligation </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_RepaymentsAndProceedsFromRelatedPartyDebt" xlink:label="OPTI_RepaymentsAndProceedsFromRelatedPartyDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_RepaymentsAndProceedsFromRelatedPartyDebt" xlink:to="OPTI_RepaymentsAndProceedsFromRelatedPartyDebt_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OPTI_RepaymentsAndProceedsFromRelatedPartyDebt_lbl" xml:lang="en-US"> Repayment of related parties </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US"> Net cash provided by financing activities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl" xml:lang="en-US"> Net increase (decrease) in cash </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_lbl" xml:lang="en-US"> Cash beginning of period </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_2_lbl" xml:lang="en-US"> Cash end of period </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xml:lang="en-US"> Supplemental disclosures of cash flow information: </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestPaidNet" xlink:label="us-gaap_InterestPaidNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaidNet" xlink:to="us-gaap_InterestPaidNet_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestPaidNet_lbl" xml:lang="en-US"> Cash paid for interest </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxesPaidNet" xlink:label="us-gaap_IncomeTaxesPaidNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxesPaidNet" xlink:to="us-gaap_IncomeTaxesPaidNet_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxesPaidNet_lbl" xml:lang="en-US"> Cash paid for income taxes </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xml:lang="en-US"> Non-Cash Investing and Financing Activities: </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_FairValueOfWarrantsRecordedAsDebtDiscount" xlink:label="OPTI_FairValueOfWarrantsRecordedAsDebtDiscount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FairValueOfWarrantsRecordedAsDebtDiscount" xlink:to="OPTI_FairValueOfWarrantsRecordedAsDebtDiscount_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_FairValueOfWarrantsRecordedAsDebtDiscount_lbl" xml:lang="en-US"> Fair value of warrants recorded as a debt discount </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_TransferOfDepositsOnPurchaseOfEquipmentToPropertyAndEquipment" xlink:label="OPTI_TransferOfDepositsOnPurchaseOfEquipmentToPropertyAndEquipment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_TransferOfDepositsOnPurchaseOfEquipmentToPropertyAndEquipment" xlink:to="OPTI_TransferOfDepositsOnPurchaseOfEquipmentToPropertyAndEquipment_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_TransferOfDepositsOnPurchaseOfEquipmentToPropertyAndEquipment_lbl" xml:lang="en-US"> Transfer of deposits on purchase of equipment to property and equipment </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ReclassificationOfVendorDepositsToPropertyAndEquipment" xlink:label="OPTI_ReclassificationOfVendorDepositsToPropertyAndEquipment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ReclassificationOfVendorDepositsToPropertyAndEquipment" xlink:to="OPTI_ReclassificationOfVendorDepositsToPropertyAndEquipment_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ReclassificationOfVendorDepositsToPropertyAndEquipment_lbl" xml:lang="en-US"> Reclassification of vendor deposits to property and equipment </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ReclassificationOfVendorDepositsToInventory" xlink:label="OPTI_ReclassificationOfVendorDepositsToInventory"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ReclassificationOfVendorDepositsToInventory" xlink:to="OPTI_ReclassificationOfVendorDepositsToInventory_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ReclassificationOfVendorDepositsToInventory_lbl" xml:lang="en-US"> Reclassification of vendor deposits to inventory </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LoansAssumed1" xlink:label="us-gaap_LoansAssumed1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansAssumed1" xlink:to="us-gaap_LoansAssumed1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansAssumed1_lbl" xml:lang="en-US"> Issuance of loan payable for vehicle purchase </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xml:lang="en-US"> Organization, Consolidation and Presentation of Financial Statements [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NatureOfOperations" xlink:label="us-gaap_NatureOfOperations"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NatureOfOperations" xlink:to="us-gaap_NatureOfOperations_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NatureOfOperations_lbl" xml:lang="en-US"> Basis of Presentation and Liquidity </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_AccountingPoliciesAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl" xml:lang="en-US"> Accounting Policies [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xml:lang="en-US"> Significant Accounting Policies </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" xml:lang="en-US"> Property, Plant and Equipment [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xml:lang="en-US"> Property and Equipment </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_DisclosureEarnoutAndRoyaltyObligationsAbstract" xlink:label="OPTI_DisclosureEarnoutAndRoyaltyObligationsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DisclosureEarnoutAndRoyaltyObligationsAbstract" xlink:to="OPTI_DisclosureEarnoutAndRoyaltyObligationsAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_DisclosureEarnoutAndRoyaltyObligationsAbstract_lbl" xml:lang="en-US"> Earnout And Royalty Obligations </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_EarnoutAndRoyaltyObligationsDisclosureTextBlock" xlink:label="OPTI_EarnoutAndRoyaltyObligationsDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EarnoutAndRoyaltyObligationsDisclosureTextBlock" xlink:to="OPTI_EarnoutAndRoyaltyObligationsDisclosureTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_EarnoutAndRoyaltyObligationsDisclosureTextBlock_lbl" xml:lang="en-US"> Earnout and Royalty Obligations </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_DisclosureSeniorConvertibleNotesPayableAndWarrantsAbstract" xlink:label="OPTI_DisclosureSeniorConvertibleNotesPayableAndWarrantsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DisclosureSeniorConvertibleNotesPayableAndWarrantsAbstract" xlink:to="OPTI_DisclosureSeniorConvertibleNotesPayableAndWarrantsAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_DisclosureSeniorConvertibleNotesPayableAndWarrantsAbstract_lbl" xml:lang="en-US"> Senior Convertible Notes Payable And Warrants </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_SeniorConvertibleNotesPayableAndWarrantsTextBlock" xlink:label="OPTI_SeniorConvertibleNotesPayableAndWarrantsTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_SeniorConvertibleNotesPayableAndWarrantsTextBlock" xlink:to="OPTI_SeniorConvertibleNotesPayableAndWarrantsTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_SeniorConvertibleNotesPayableAndWarrantsTextBlock_lbl" xml:lang="en-US"> Senior Convertible Notes Payable and Warrants </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_DebtDisclosureAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtDisclosureAbstract_lbl" xml:lang="en-US"> Debt Disclosure [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtDisclosureTextBlock" xlink:label="us-gaap_DebtDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtDisclosureTextBlock" xlink:to="us-gaap_DebtDisclosureTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtDisclosureTextBlock_lbl" xml:lang="en-US"> Note Payable </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_LoanPayableTextBlock" xlink:label="OPTI_LoanPayableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_LoanPayableTextBlock" xlink:to="OPTI_LoanPayableTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_LoanPayableTextBlock_lbl" xml:lang="en-US"> Loans payable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityAbstract" xlink:label="us-gaap_EquityAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_EquityAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityAbstract_lbl" xml:lang="en-US"> Equity [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xml:lang="en-US"> Shareholders’ Equity (Deficit) </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xml:lang="en-US"> Commitments and Contingencies Disclosure [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xml:lang="en-US"> Commitments and Contingencies </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxDisclosureAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureAbstract_lbl" xml:lang="en-US"> Income Tax Disclosure [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xml:lang="en-US"> Income Taxes </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="us-gaap_RelatedPartyTransactionsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsAbstract" xlink:to="us-gaap_RelatedPartyTransactionsAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsAbstract_lbl" xml:lang="en-US"> Related Party Transactions [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:to="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl" xml:lang="en-US"> Related Party Transactions </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventsAbstract" xlink:label="us-gaap_SubsequentEventsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsAbstract" xlink:to="us-gaap_SubsequentEventsAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventsAbstract_lbl" xml:lang="en-US"> Subsequent Events [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventsTextBlock" xlink:label="us-gaap_SubsequentEventsTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsTextBlock" xlink:to="us-gaap_SubsequentEventsTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xml:lang="en-US"> Subsequent Events </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="us-gaap_InventoryDisclosureAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureAbstract" xlink:to="us-gaap_InventoryDisclosureAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryDisclosureAbstract_lbl" xml:lang="en-US"> Inventory Disclosure [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InventoryDisclosureTextBlock" xlink:label="us-gaap_InventoryDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureTextBlock" xlink:to="us-gaap_InventoryDisclosureTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl" xml:lang="en-US"> Inventory </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_lbl" xml:lang="en-US"> Goodwill and Intangible Assets Disclosure [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:to="us-gaap_IntangibleAssetsDisclosureTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock_lbl" xml:lang="en-US"> Intangible Assets and Contingent Earnout Liability </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UseOfEstimates_lbl" xml:lang="en-US"> Use of Estimates </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InventoryPolicyTextBlock" xlink:label="us-gaap_InventoryPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryPolicyTextBlock" xlink:to="us-gaap_InventoryPolicyTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryPolicyTextBlock_lbl" xml:lang="en-US"> Inventory </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xml:lang="en-US"> Property and Equipment </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_DeferredOfferingCostsPolicyTextBlock" xlink:label="OPTI_DeferredOfferingCostsPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DeferredOfferingCostsPolicyTextBlock" xlink:to="OPTI_DeferredOfferingCostsPolicyTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_DeferredOfferingCostsPolicyTextBlock_lbl" xml:lang="en-US"> Deferred Offering Costs </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:label="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:to="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock_lbl" xml:lang="en-US"> Revenue Recognition </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerSharePolicyTextBlock" xlink:to="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xml:lang="en-US"> Loss per Common Share </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:to="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xml:lang="en-US"> Stock Compensation Expense </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="us-gaap_IncomeTaxPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPolicyTextBlock" xlink:to="us-gaap_IncomeTaxPolicyTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xml:lang="en-US"> Income Taxes </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:to="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl" xml:lang="en-US"> Research and Development </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:to="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl" xml:lang="en-US"> Fair Value of Financial Instruments </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xml:lang="en-US"> Recent Accounting Pronouncements </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskCreditRisk" xlink:label="us-gaap_ConcentrationRiskCreditRisk"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskCreditRisk" xlink:to="us-gaap_ConcentrationRiskCreditRisk_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskCreditRisk_lbl" xml:lang="en-US"> Concentration Risks </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:label="us-gaap_SegmentReportingPolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:to="us-gaap_SegmentReportingPolicyPolicyTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingPolicyPolicyTextBlock_lbl" xml:lang="en-US"> Segment Reporting </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ScheduleOfEstimatedUsefulLivesOfPropertyAndEquipmentTableTextBlock" xlink:label="OPTI_ScheduleOfEstimatedUsefulLivesOfPropertyAndEquipmentTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ScheduleOfEstimatedUsefulLivesOfPropertyAndEquipmentTableTextBlock" xlink:to="OPTI_ScheduleOfEstimatedUsefulLivesOfPropertyAndEquipmentTableTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ScheduleOfEstimatedUsefulLivesOfPropertyAndEquipmentTableTextBlock_lbl" xml:lang="en-US"> Schedule of Estimated Useful Lives of Property and Equipment </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xml:lang="en-US"> Schedule of Anti-Dilutive Securities of Earning Per Share </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xml:lang="en-US"> Schedule of Property and Equipment </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDebtTableTextBlock" xlink:label="us-gaap_ScheduleOfDebtTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDebtTableTextBlock" xlink:to="us-gaap_ScheduleOfDebtTableTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDebtTableTextBlock_lbl" xml:lang="en-US"> Schedule of Senior Convertible Notes Payable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShortTermDebtTextBlock" xlink:label="us-gaap_ScheduleOfShortTermDebtTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShortTermDebtTextBlock" xlink:to="us-gaap_ScheduleOfShortTermDebtTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShortTermDebtTextBlock_lbl" xml:lang="en-US"> Schedule of Loans Payable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" xlink:label="us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" xlink:to="us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock_lbl" xml:lang="en-US"> Summary of Warrants </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ScheduleOfShareBasedCompensationWarrantsByExercisePriceRangeTextBlock" xlink:label="OPTI_ScheduleOfShareBasedCompensationWarrantsByExercisePriceRangeTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ScheduleOfShareBasedCompensationWarrantsByExercisePriceRangeTextBlock" xlink:to="OPTI_ScheduleOfShareBasedCompensationWarrantsByExercisePriceRangeTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ScheduleOfShareBasedCompensationWarrantsByExercisePriceRangeTextBlock_lbl" xml:lang="en-US"> Summary of Outstanding Warrants Exercise Price </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xml:lang="en-US"> Summary of Options </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock_lbl" xml:lang="en-US"> Summary of Outstanding Options Exercise Price </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Effective Income Tax Rate </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xml:lang="en-US"> Schedule of Components of Deferred Taxes </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:to="us-gaap_ScheduleOfInventoryCurrentTableTextBlock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock_lbl" xml:lang="en-US"> Schedule of Inventory </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTable" xlink:label="us-gaap_SubsequentEventTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_SubsequentEventTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTable_lbl" xml:lang="en-US"> Subsequent Event [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventLineItems" xlink:label="us-gaap_SubsequentEventLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventLineItems" xlink:to="us-gaap_SubsequentEventLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventLineItems_lbl" xml:lang="en-US"> Subsequent Event [Line Items] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_4_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_NetIncomeLoss_4_lbl" xml:lang="en-US"> Net loss </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_2_lbl" xml:lang="en-US"> Net cash provided by operating activities </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_4_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_StockholdersEquity_4_lbl" xml:lang="en-US"> Stockholders' Equity Attributable to Parent </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_lbl" xml:lang="en-US"> Proceeds from issuance of private placement </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xml:lang="en-US"> Property, Plant and Equipment [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xml:lang="en-US"> Property, Plant and Equipment [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives" xlink:label="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives" xlink:to="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_lbl" xml:lang="en-US"> Property, plant and equipment, estimated useful lives </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_lbl" xml:lang="en-US"> Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_lbl" xml:lang="en-US"> Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xml:lang="en-US"> Anti-dilutive securities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfProductInformationTable" xlink:label="us-gaap_ScheduleOfProductInformationTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfProductInformationTable" xlink:to="us-gaap_ScheduleOfProductInformationTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfProductInformationTable_lbl" xml:lang="en-US"> Schedule of Product Information [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProductInformationLineItems" xlink:label="us-gaap_ProductInformationLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductInformationLineItems" xlink:to="us-gaap_ProductInformationLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductInformationLineItems_lbl" xml:lang="en-US"> Product Information [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashFDICInsuredAmount" xlink:label="us-gaap_CashFDICInsuredAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashFDICInsuredAmount" xlink:to="us-gaap_CashFDICInsuredAmount_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashFDICInsuredAmount_lbl" xml:lang="en-US"> Cash, FDIC insured amount </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="us-gaap_ConcentrationRiskPercentage1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskPercentage1" xlink:to="us-gaap_ConcentrationRiskPercentage1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xml:lang="en-US"> Concentration risk, percentage </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentGross" xlink:to="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xml:lang="en-US"> Total cost </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_2_lbl" xml:lang="en-US"> Accumulated depreciation </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_2_lbl" xml:lang="en-US"> Net book value </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentTable_lbl" xml:lang="en-US"> Schedule of Long-Term Debt Instruments [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xml:lang="en-US"> Debt Instrument [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xml:lang="en-US"> Face amount </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="OPTI_ReclassificationOfVendorDepositsToPropertyAndEquipment_2_lbl" xml:lang="en-US"> Vendor deposits to property and equipment </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear" xlink:label="us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear" xlink:to="us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear_lbl" xml:lang="en-US"> Remaining purchase obligation </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PurchaseObligation" xlink:label="us-gaap_PurchaseObligation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PurchaseObligation" xlink:to="us-gaap_PurchaseObligation_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PurchaseObligation_lbl" xml:lang="en-US"> Purchase obligation </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_EarnoutPaymentsDescription" xlink:label="OPTI_EarnoutPaymentsDescription"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EarnoutPaymentsDescription" xlink:to="OPTI_EarnoutPaymentsDescription_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_EarnoutPaymentsDescription_lbl" xml:lang="en-US"> Earnout payments, description </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireIntangibleAssets" xlink:label="us-gaap_PaymentsToAcquireIntangibleAssets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireIntangibleAssets" xlink:to="us-gaap_PaymentsToAcquireIntangibleAssets_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireIntangibleAssets_lbl" xml:lang="en-US"> Payments to acquire intangible assets </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_2_lbl" xml:lang="en-US"> Revenues </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdvanceRoyalties" xlink:label="us-gaap_AdvanceRoyalties"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdvanceRoyalties" xlink:to="us-gaap_AdvanceRoyalties_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdvanceRoyalties_lbl" xml:lang="en-US"> Advance royalties </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RoyaltyExpense" xlink:label="us-gaap_RoyaltyExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RoyaltyExpense" xlink:to="us-gaap_RoyaltyExpense_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RoyaltyExpense_lbl" xml:lang="en-US"> Royalty expense </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RoyaltyGuaranteesCommitmentsAmount" xlink:label="us-gaap_RoyaltyGuaranteesCommitmentsAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RoyaltyGuaranteesCommitmentsAmount" xlink:to="us-gaap_RoyaltyGuaranteesCommitmentsAmount_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RoyaltyGuaranteesCommitmentsAmount_lbl" xml:lang="en-US"> Royalty guarantees commitments amount </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PercentageOfConsiderationReceived" xlink:label="OPTI_PercentageOfConsiderationReceived"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PercentageOfConsiderationReceived" xlink:to="OPTI_PercentageOfConsiderationReceived_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PercentageOfConsiderationReceived_lbl" xml:lang="en-US"> Percentage of consideration received </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" xlink:label="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" xlink:to="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_lbl" xml:lang="en-US"> Strategic transaction consideration </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ConcentrationRiskPercentage" xlink:label="OPTI_ConcentrationRiskPercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ConcentrationRiskPercentage" xlink:to="OPTI_ConcentrationRiskPercentage_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="OPTI_ConcentrationRiskPercentage_lbl" xml:lang="en-US"> Concentration risk, percentage </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ConvertibleNotesPayableGross" xlink:label="OPTI_ConvertibleNotesPayableGross"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ConvertibleNotesPayableGross" xlink:to="OPTI_ConvertibleNotesPayableGross_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ConvertibleNotesPayableGross_lbl" xml:lang="en-US"> Senior convertible notes payable </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountCurrent_2_lbl" xml:lang="en-US"> Less debt discount </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ConvertibleNotesPayableCurrent_2_lbl" xml:lang="en-US"> Total senior convertible notes payable, net </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NotesIssued1" xlink:label="us-gaap_NotesIssued1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesIssued1" xlink:to="us-gaap_NotesIssued1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotesIssued1_lbl" xml:lang="en-US"> Notes issued </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromIssuanceOfWarrants" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfWarrants" xlink:to="us-gaap_ProceedsFromIssuanceOfWarrants_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants_lbl" xml:lang="en-US"> Proceeds from warrants </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromIssuanceOfDebt" xlink:label="us-gaap_ProceedsFromIssuanceOfDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfDebt_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfDebt_lbl" xml:lang="en-US"> Proceeds from issuance of debt </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage" xlink:label="us-gaap_DebtInstrumentRedemptionPricePercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRedemptionPricePercentage" xlink:to="us-gaap_DebtInstrumentRedemptionPricePercentage_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentRedemptionPricePercentage_lbl" xml:lang="en-US"> Debt instrument redemption price percentage </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnamortizedDiscount" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscount" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" xml:lang="en-US"> Debt Instrument, Unamortized Discount </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProfessionalFees" xlink:label="us-gaap_ProfessionalFees"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProfessionalFees" xlink:to="us-gaap_ProfessionalFees_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProfessionalFees_lbl" xml:lang="en-US"> Legal fees </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_WarrantsExercisablePricePercentage" xlink:label="OPTI_WarrantsExercisablePricePercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_WarrantsExercisablePricePercentage" xlink:to="OPTI_WarrantsExercisablePricePercentage_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_WarrantsExercisablePricePercentage_lbl" xml:lang="en-US"> Warrants exercisable price percentage </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xml:lang="en-US"> Warrants exercise price </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAdjustmentOfWarrants" xlink:to="us-gaap_FairValueAdjustmentOfWarrants_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl" xml:lang="en-US"> Fair value of warrants </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtFairValue" xlink:label="us-gaap_LongTermDebtFairValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtFairValue" xlink:to="us-gaap_LongTermDebtFairValue_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtFairValue_lbl" xml:lang="en-US"> Fair value of debt </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquitySecuritiesFvNiMeasurementInput" xlink:label="us-gaap_EquitySecuritiesFvNiMeasurementInput"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquitySecuritiesFvNiMeasurementInput" xlink:to="us-gaap_EquitySecuritiesFvNiMeasurementInput_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquitySecuritiesFvNiMeasurementInput_lbl" xml:lang="en-US"> Stock price </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ExercisableWarrantPercentageAmount" xlink:label="OPTI_ExercisableWarrantPercentageAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ExercisableWarrantPercentageAmount" xlink:to="OPTI_ExercisableWarrantPercentageAmount_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ExercisableWarrantPercentageAmount_lbl" xml:lang="en-US"> Exercisable warrant percentage amount </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_EquitySecuritiesFvNiMeasurementInputTerm" xlink:label="OPTI_EquitySecuritiesFvNiMeasurementInputTerm"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EquitySecuritiesFvNiMeasurementInputTerm" xlink:to="OPTI_EquitySecuritiesFvNiMeasurementInputTerm_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_EquitySecuritiesFvNiMeasurementInputTerm_lbl" xml:lang="en-US"> Expected term </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_CommonStockPercentageAmount" xlink:label="OPTI_CommonStockPercentageAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_CommonStockPercentageAmount" xlink:to="OPTI_CommonStockPercentageAmount_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_CommonStockPercentageAmount_lbl" xml:lang="en-US"> Common stock percentage amount </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtWeightedAverageInterestRate" xlink:label="us-gaap_DebtWeightedAverageInterestRate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtWeightedAverageInterestRate" xlink:to="us-gaap_DebtWeightedAverageInterestRate_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtWeightedAverageInterestRate_lbl" xml:lang="en-US"> Debt, weighted average interest rate </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtTerm" xlink:label="us-gaap_LongTermDebtTerm"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtTerm" xlink:to="us-gaap_LongTermDebtTerm_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtTerm_lbl" xml:lang="en-US"> Long-term debt, term </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtAndEquitySecuritiesGainLoss" xlink:label="us-gaap_DebtAndEquitySecuritiesGainLoss"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtAndEquitySecuritiesGainLoss" xlink:to="us-gaap_DebtAndEquitySecuritiesGainLoss_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtAndEquitySecuritiesGainLoss_lbl" xml:lang="en-US"> Gain loss on equity securities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentDescription" xlink:label="us-gaap_DebtInstrumentDescription"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentDescription" xlink:to="us-gaap_DebtInstrumentDescription_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentDescription_lbl" xml:lang="en-US"> Debt Instrument, Description </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfWarrantOrRightReasonForIssuingToNonemployees" xlink:label="us-gaap_ClassOfWarrantOrRightReasonForIssuingToNonemployees"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightReasonForIssuingToNonemployees" xlink:to="us-gaap_ClassOfWarrantOrRightReasonForIssuingToNonemployees_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightReasonForIssuingToNonemployees_lbl" xml:lang="en-US"> Warrants description </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PercentageOfProrataSecurities" xlink:label="OPTI_PercentageOfProrataSecurities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PercentageOfProrataSecurities" xlink:to="OPTI_PercentageOfProrataSecurities_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PercentageOfProrataSecurities_lbl" xml:lang="en-US"> Percentage of prorata securities </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockDiscountOnShares" xlink:label="us-gaap_CommonStockDiscountOnShares"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockDiscountOnShares" xlink:to="us-gaap_CommonStockDiscountOnShares_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockDiscountOnShares_lbl" xml:lang="en-US"> Original issue discount </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants" xlink:label="us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants" xlink:to="us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants_lbl" xml:lang="en-US"> Fair value of warrants issued </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssued1" xlink:label="us-gaap_StockIssued1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssued1" xlink:to="us-gaap_StockIssued1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssued1_lbl" xml:lang="en-US"> Debt discount stock issued </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentForAmortization" xlink:label="us-gaap_AdjustmentForAmortization"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentForAmortization" xlink:to="us-gaap_AdjustmentForAmortization_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentForAmortization_lbl" xml:lang="en-US"> Remaining unamortized discount </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestPayableCurrent" xlink:label="us-gaap_InterestPayableCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPayableCurrent" xlink:to="us-gaap_InterestPayableCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestPayableCurrent_lbl" xml:lang="en-US"> Accrued interest </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_AccruedLiabilitiesCurrent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xml:lang="en-US"> Accrued interest </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_2_lbl" xml:lang="en-US"> Shares of common stock potentially issuable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LegalFees" xlink:label="us-gaap_LegalFees"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LegalFees" xlink:to="us-gaap_LegalFees_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LegalFees_lbl" xml:lang="en-US"> Legal fees </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PercentageOfCommonStockPurchasePrice" xlink:label="OPTI_PercentageOfCommonStockPurchasePrice"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PercentageOfCommonStockPurchasePrice" xlink:to="OPTI_PercentageOfCommonStockPurchasePrice_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PercentageOfCommonStockPurchasePrice_lbl" xml:lang="en-US"> Percentage of common stock purchase price </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharePrice" xlink:to="us-gaap_SharePrice_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharePrice_lbl" xml:lang="en-US"> Share Price </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_2_lbl" xml:lang="en-US"> Number of shares of common stock </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_2_lbl" xml:lang="en-US"> Aggregate value of common stock </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FinancingCosts" xlink:to="OPTI_FinancingCosts_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="OPTI_FinancingCosts_3_lbl" xml:lang="en-US"> Financing Costs </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInInterestPayableNet" xlink:label="us-gaap_IncreaseDecreaseInInterestPayableNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInInterestPayableNet" xlink:to="us-gaap_IncreaseDecreaseInInterestPayableNet_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInInterestPayableNet_lbl" xml:lang="en-US"> Changes in interest payable </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentFaceAmount_2_lbl" xml:lang="en-US"> Aggregate amount </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NotesPayable" xlink:label="us-gaap_NotesPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayable" xlink:to="us-gaap_NotesPayable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NotesPayable_lbl" xml:lang="en-US"> Note payable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentDecreaseForgiveness" xlink:label="us-gaap_DebtInstrumentDecreaseForgiveness"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentDecreaseForgiveness" xlink:to="us-gaap_DebtInstrumentDecreaseForgiveness_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentDecreaseForgiveness_lbl" xml:lang="en-US"> Gain on forgiveness of debt </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentFaceAmount_3_lbl" xml:lang="en-US"> Principal amount </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTerm" xlink:label="us-gaap_DebtInstrumentTerm"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTerm" xlink:to="us-gaap_DebtInstrumentTerm_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentTerm_lbl" xml:lang="en-US"> Debt instrument, term </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xml:lang="en-US"> Debt interest rate </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentPeriodicPayment" xlink:label="us-gaap_DebtInstrumentPeriodicPayment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentPeriodicPayment" xlink:to="us-gaap_DebtInstrumentPeriodicPayment_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentPeriodicPayment_lbl" xml:lang="en-US"> Debt principal and interest payments </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentCollateral" xlink:label="us-gaap_DebtInstrumentCollateral"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCollateral" xlink:to="us-gaap_DebtInstrumentCollateral_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentCollateral_lbl" xml:lang="en-US"> Debt instrument collateral </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LoansPayable" xlink:label="us-gaap_LoansPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayable" xlink:to="us-gaap_LoansPayable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LoansPayable_lbl" xml:lang="en-US"> Loans payable </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayableCurrent" xlink:to="us-gaap_LoansPayableCurrent_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LoansPayableCurrent_2_lbl" xml:lang="en-US"> Loan payable, current </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAnnualPrincipalPayment" xlink:label="us-gaap_DebtInstrumentAnnualPrincipalPayment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAnnualPrincipalPayment" xlink:to="us-gaap_DebtInstrumentAnnualPrincipalPayment_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentAnnualPrincipalPayment_lbl" xml:lang="en-US"> Principal payments </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:to="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xml:lang="en-US"> Debt interest rate </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentPrincipal"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentPeriodicPaymentPrincipal" xlink:to="us-gaap_DebtInstrumentPeriodicPaymentPrincipal_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentPrincipal_lbl" xml:lang="en-US"> Debt principal payments </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_lbl" xml:lang="en-US"> Accumulated Other Comprehensive Income (Loss) [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_lbl" xml:lang="en-US"> Accumulated Other Comprehensive Income (Loss) [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_lbl" xml:lang="en-US"> Warrants, Balance outstanding </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageGrantDateFairValue" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageGrantDateFairValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageGrantDateFairValue_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted Average Exercise Price, Balance outstanding </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted_lbl" xlink:type="arc"/>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGrantedWeightedAverageGrantDateFairValue" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGrantedWeightedAverageGrantDateFairValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGrantedWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGrantedWeightedAverageGrantDateFairValue_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGrantedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted Average Exercise Price, granted </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised_lbl" xml:lang="en-US"> Warrants exercised </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisedWeightedAverageGrantDateFairValue" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisedWeightedAverageGrantDateFairValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisedWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisedWeightedAverageGrantDateFairValue_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted Average Exercise Price, exercised </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations_lbl" xml:lang="en-US"> Warrants expired or forfeited </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirationsWeightedAverageGrantDateFairValue" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirationsWeightedAverageGrantDateFairValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirationsWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirationsWeightedAverageGrantDateFairValue_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirationsWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted Average Exercise Price, expired or forfeited </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_2_lbl" xml:lang="en-US"> Warrants, Balance outstanding </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageGrantDateFairValue_2_lbl" xml:lang="en-US"> Weighted Average Exercise Price, Balance outstanding </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber_lbl" xml:lang="en-US"> Warrants, Balance exercisable </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Weighted Average Exercise Price, Balance exercisable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfWarrantOrRightTable" xlink:label="us-gaap_ClassOfWarrantOrRightTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightTable" xlink:to="us-gaap_ClassOfWarrantOrRightTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightTable_lbl" xml:lang="en-US"> Class of Warrant or Right [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfWarrantOrRightLineItems" xlink:label="us-gaap_ClassOfWarrantOrRightLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightLineItems_lbl" xml:lang="en-US"> Class of Warrant or Right [Line Items] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_2_lbl" xml:lang="en-US"> Exercise Price Per Share </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantsAndRightsOutstanding" xlink:label="us-gaap_WarrantsAndRightsOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantsAndRightsOutstanding" xlink:to="us-gaap_WarrantsAndRightsOutstanding_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WarrantsAndRightsOutstanding_lbl" xml:lang="en-US"> Outstanding share </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantsAndRightsOutstandingTerm" xlink:label="us-gaap_WarrantsAndRightsOutstandingTerm"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantsAndRightsOutstandingTerm" xlink:to="us-gaap_WarrantsAndRightsOutstandingTerm_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WarrantsAndRightsOutstandingTerm_lbl" xml:lang="en-US"> Life (Years) </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRights1" xlink:label="OPTI_ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRights1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRights1" xlink:to="OPTI_ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRights1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRights1_lbl" xml:lang="en-US"> Weighted Average Exercise Price </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_WarrantsAndRightsExercisableOutstanding" xlink:label="OPTI_WarrantsAndRightsExercisableOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_WarrantsAndRightsExercisableOutstanding" xlink:to="OPTI_WarrantsAndRightsExercisableOutstanding_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_WarrantsAndRightsExercisableOutstanding_lbl" xml:lang="en-US"> Exercisable share </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ClassOfWarrantOrRightExercisableWeightedAverageExercisePriceOfWarrantsOrRights1" xlink:label="OPTI_ClassOfWarrantOrRightExercisableWeightedAverageExercisePriceOfWarrantsOrRights1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ClassOfWarrantOrRightExercisableWeightedAverageExercisePriceOfWarrantsOrRights1" xlink:to="OPTI_ClassOfWarrantOrRightExercisableWeightedAverageExercisePriceOfWarrantsOrRights1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ClassOfWarrantOrRightExercisableWeightedAverageExercisePriceOfWarrantsOrRights1_lbl" xml:lang="en-US"> Exercisable Weighted Average Exercise Price </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US"> Options, Balance outstanding </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted Average Exercise Price, Balance outstanding </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:type="arc"/>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted Average Exercise Price, granted </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_2_lbl" xml:lang="en-US"> Options exercised </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted Average Exercise Price, exercised </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations_2_lbl" xml:lang="en-US"> Options expired or forfeited </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted Average Exercise Price, expired or forfeited </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_2_lbl" xml:lang="en-US"> Options, Balance outstanding </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_2_lbl" xml:lang="en-US"> Weighted Average Exercise Price, Balance outstanding </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xml:lang="en-US"> Options, Balance exercisable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted Average Exercise Price, Balance exercisable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:to="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_lbl" xml:lang="en-US"> Share-Based Payment Arrangement, Option, Exercise Price Range [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_lbl" xml:lang="en-US"> Share-Based Payment Arrangement, Option, Exercise Price Range [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_lbl" xml:lang="en-US"> Exercise Price Per Share </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_3_lbl" xlink:type="arc"/>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl" xml:lang="en-US"> Outstanding, Life (Years) </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_3_lbl" xml:lang="en-US"> Outstanding, Weighted Average Exercise Price </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_2_lbl" xlink:type="arc"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_2_lbl" xml:lang="en-US"> Exercisable, Weighted Average Exercise Price </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_2_lbl" xml:lang="en-US"> Common stock par value </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PreferredStockSharesDesginated" xlink:label="OPTI_PreferredStockSharesDesginated"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PreferredStockSharesDesginated" xlink:to="OPTI_PreferredStockSharesDesginated_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PreferredStockSharesDesginated_lbl" xml:lang="en-US"> Preferred stock, shares desginated </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_2_lbl" xml:lang="en-US"> Preferred stock par value </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_2_lbl" xml:lang="en-US"> Net proceeds from common stock </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_3_lbl" xml:lang="en-US"> Number of share issued </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssuedPricePerShare" xlink:to="us-gaap_SharesIssuedPricePerShare_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesIssuedPricePerShare_lbl" xml:lang="en-US"> Shares issued price per share </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ClassOfWarrantOrRightExpirationDate" xlink:label="OPTI_ClassOfWarrantOrRightExpirationDate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ClassOfWarrantOrRightExpirationDate" xlink:to="OPTI_ClassOfWarrantOrRightExpirationDate_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ClassOfWarrantOrRightExpirationDate_lbl" xml:lang="en-US"> Expiration date </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_2_lbl" xml:lang="en-US"> Number of shares issued service </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices_2_lbl" xml:lang="en-US"> Share based compensation </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:to="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xml:lang="en-US"> Number of warrant issued </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTermWarrantsOutstandingAndExercisable" xlink:label="OPTI_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTermWarrantsOutstandingAndExercisable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTermWarrantsOutstandingAndExercisable" xlink:to="OPTI_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTermWarrantsOutstandingAndExercisable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTermWarrantsOutstandingAndExercisable_lbl" xml:lang="en-US"> Weighted-average remaining contractual life </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" xlink:type="arc"/>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_lbl" xml:lang="en-US"> Exercisable intrinsic value </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValuePerShare" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValuePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValuePerShare" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValuePerShare_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValuePerShare_lbl" xml:lang="en-US"> Estimated market value </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockPricePerShare" xlink:to="us-gaap_SaleOfStockPricePerShare_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SaleOfStockPricePerShare_lbl" xml:lang="en-US"> Sale of stock price </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_CommonStockSharesPurchased" xlink:label="OPTI_CommonStockSharesPurchased"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_CommonStockSharesPurchased" xlink:to="OPTI_CommonStockSharesPurchased_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_CommonStockSharesPurchased_lbl" xml:lang="en-US"> Common shares purchased </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_WarrantsToPurchaseCommonStock" xlink:label="OPTI_WarrantsToPurchaseCommonStock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_WarrantsToPurchaseCommonStock" xlink:to="OPTI_WarrantsToPurchaseCommonStock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_WarrantsToPurchaseCommonStock_lbl" xml:lang="en-US"> Warrants to purchase, shares </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:to="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_lbl" xml:lang="en-US"> Exercise price </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1" xlink:label="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1" xlink:to="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1_lbl" xml:lang="en-US"> Warrants purchase </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PercentageOfWarrantsExercisable" xlink:label="OPTI_PercentageOfWarrantsExercisable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PercentageOfWarrantsExercisable" xlink:to="OPTI_PercentageOfWarrantsExercisable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PercentageOfWarrantsExercisable_lbl" xml:lang="en-US"> Percentage of warrants exercisable </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherExpenses" xlink:label="us-gaap_OtherExpenses"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherExpenses" xlink:to="us-gaap_OtherExpenses_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherExpenses_lbl" xml:lang="en-US"> Other expenses </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeBenefitPlan" xlink:label="us-gaap_StockIssuedDuringPeriodValueEmployeeBenefitPlan"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueEmployeeBenefitPlan" xlink:to="us-gaap_StockIssuedDuringPeriodValueEmployeeBenefitPlan_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueEmployeeBenefitPlan_lbl" xml:lang="en-US"> Employee benefit plan </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquitySecuritiesFvNiMeasurementInput_2_lbl" xml:lang="en-US"> Risk-free interest rate </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllocatedShareBasedCompensationExpense" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xml:lang="en-US"> Share based compensation expense </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xlink:type="arc"/>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeBenefitPlan" xlink:label="us-gaap_StockIssuedDuringPeriodSharesEmployeeBenefitPlan"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesEmployeeBenefitPlan" xlink:to="us-gaap_StockIssuedDuringPeriodSharesEmployeeBenefitPlan_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesEmployeeBenefitPlan_lbl" xml:lang="en-US"> Shares of common stock </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_4_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_4_lbl" xml:lang="en-US"> Intrinsic value </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_3_lbl" xml:lang="en-US"> Intrinsic value </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_4_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_4_lbl" xml:lang="en-US"> Estimated market value </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate_lbl" xlink:type="arc"/>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OfficersCompensation" xlink:label="us-gaap_OfficersCompensation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OfficersCompensation" xlink:to="us-gaap_OfficersCompensation_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OfficersCompensation_lbl" xml:lang="en-US"> Base salary </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeveranceCosts1" xlink:label="us-gaap_SeveranceCosts1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeveranceCosts1" xlink:to="us-gaap_SeveranceCosts1_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SeveranceCosts1_lbl" xml:lang="en-US"> Severance payment </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2_lbl" xml:lang="en-US"> Weighted average expiration period </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl" xml:lang="en-US"> Number of shares sales </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeBenefitsAndShareBasedCompensation" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeBenefitsAndShareBasedCompensation" xlink:to="us-gaap_EmployeeBenefitsAndShareBasedCompensation_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation_lbl" xml:lang="en-US"> Employee Benefits and Share-Based Compensation </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_CommonStockWarrantShare" xlink:label="OPTI_CommonStockWarrantShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_CommonStockWarrantShare" xlink:to="OPTI_CommonStockWarrantShare_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_CommonStockWarrantShare_lbl" xml:lang="en-US"> Common stock warrant share </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_2_lbl" xml:lang="en-US"> Proceeds from Issuance of Private Placement </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable" xlink:label="us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable" xlink:to="us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable_lbl" xml:lang="en-US"> Warrant expires date </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesIssued" xlink:label="us-gaap_SharesIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssued" xlink:to="us-gaap_SharesIssued_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesIssued_lbl" xml:lang="en-US"> Shares issued </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl" xml:lang="en-US"> Proceeds from issuance initial public offering </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonVested" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonVested"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonVested" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonVested_lbl" xlink:type="arc"/>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromWarrantExercises" xlink:label="us-gaap_ProceedsFromWarrantExercises"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromWarrantExercises" xlink:to="us-gaap_ProceedsFromWarrantExercises_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromWarrantExercises_lbl" xml:lang="en-US"> Proceeds from warrant exercises </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl" xlink:type="arc"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_3_lbl" xml:lang="en-US"> Exercise price </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SalariesAndWages" xlink:label="us-gaap_SalariesAndWages"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SalariesAndWages" xlink:to="us-gaap_SalariesAndWages_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SalariesAndWages_lbl" xml:lang="en-US"> Salary and Wage, NonOfficer, Excluding Cost of Good and Service Sold </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrants" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrants"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrants" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrants_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrants_lbl" xml:lang="en-US"> [custom:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrants] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensation_lbl" xml:lang="en-US"> Share based compensation </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockOptionPlanExpense" xlink:label="us-gaap_StockOptionPlanExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockOptionPlanExpense" xlink:to="us-gaap_StockOptionPlanExpense_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockOptionPlanExpense_lbl" xml:lang="en-US"> Stock or Unit Option Plan Expense </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProfessionalFees" xlink:to="us-gaap_ProfessionalFees_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ProfessionalFees_2_lbl" xml:lang="en-US"> Professional fees </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_DeferredConsultingFees" xlink:label="OPTI_DeferredConsultingFees"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DeferredConsultingFees" xlink:to="OPTI_DeferredConsultingFees_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_DeferredConsultingFees_lbl" xml:lang="en-US"> Deferred consulting fees </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_DeferredFinancingCost" xlink:label="OPTI_DeferredFinancingCost"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DeferredFinancingCost" xlink:to="OPTI_DeferredFinancingCost_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_DeferredFinancingCost_lbl" xml:lang="en-US"> Deferred financing cost </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_MonthlyFeeForRemainingPeriod" xlink:label="OPTI_MonthlyFeeForRemainingPeriod"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MonthlyFeeForRemainingPeriod" xlink:to="OPTI_MonthlyFeeForRemainingPeriod_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_MonthlyFeeForRemainingPeriod_lbl" xml:lang="en-US"> Monthly fee for remaining period </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_2_lbl" xml:lang="en-US"> Sale of stock number of shares, issued </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromRelatedPartyDebt" xlink:label="us-gaap_ProceedsFromRelatedPartyDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromRelatedPartyDebt" xlink:to="us-gaap_ProceedsFromRelatedPartyDebt_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromRelatedPartyDebt_lbl" xml:lang="en-US"> Proceeds from related party debt </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_CommonStockPercentageOutstandingAmount" xlink:label="OPTI_CommonStockPercentageOutstandingAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_CommonStockPercentageOutstandingAmount" xlink:to="OPTI_CommonStockPercentageOutstandingAmount_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_CommonStockPercentageOutstandingAmount_lbl" xml:lang="en-US"> Common stock, outstanding percentage </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_2_lbl" xml:lang="en-US"> Proceeds from Issuance Initial Public Offering </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings" xlink:label="us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings" xlink:to="us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_lbl" xml:lang="en-US"> Restricted stock issue, shares </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_lbl" xml:lang="en-US"> Sharebased compensation shares authorized </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_2_lbl" xml:lang="en-US"> Share price </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed" xlink:label="us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed" xlink:to="us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed_lbl" xml:lang="en-US"> Principal amounta redeemed </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SalariesWagesAndOfficersCompensation" xlink:label="us-gaap_SalariesWagesAndOfficersCompensation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SalariesWagesAndOfficersCompensation" xlink:to="us-gaap_SalariesWagesAndOfficersCompensation_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SalariesWagesAndOfficersCompensation_lbl" xml:lang="en-US"> Annual base salary </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_DescriptionOfIncreaseInSalaryPercentage" xlink:label="OPTI_DescriptionOfIncreaseInSalaryPercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DescriptionOfIncreaseInSalaryPercentage" xlink:to="OPTI_DescriptionOfIncreaseInSalaryPercentage_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_DescriptionOfIncreaseInSalaryPercentage_lbl" xml:lang="en-US"> Increase in salary employment, description </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_StockOptionToPurchaseCommonStock" xlink:label="OPTI_StockOptionToPurchaseCommonStock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_StockOptionToPurchaseCommonStock" xlink:to="OPTI_StockOptionToPurchaseCommonStock_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_StockOptionToPurchaseCommonStock_lbl" xml:lang="en-US"> Stock option shares to purchase common stock </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_3_lbl" xml:lang="en-US"> Class of Warrant or Right, Exercise Price of Warrants or Rights </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate_2_lbl" xml:lang="en-US"> Stock option, expiration date </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_lbl" xml:lang="en-US"> Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_2_lbl" xml:lang="en-US"> Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_StockOptionDescription" xlink:label="OPTI_StockOptionDescription"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_StockOptionDescription" xlink:to="OPTI_StockOptionDescription_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_StockOptionDescription_lbl" xml:lang="en-US"> Stock option, description </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsTerm" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsTerm"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsTerm" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsTerm_lbl" xlink:type="arc"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GrossProfit" xlink:to="us-gaap_GrossProfit_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GrossProfit_2_lbl" xml:lang="en-US"> Gross profit </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockDividendsPerShareCashPaid" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockDividendsPerShareCashPaid" xlink:to="us-gaap_CommonStockDividendsPerShareCashPaid_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid_lbl" xml:lang="en-US"> Common stock, dividends per share </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PercentageOfCashFeePayable" xlink:label="OPTI_PercentageOfCashFeePayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PercentageOfCashFeePayable" xlink:to="OPTI_PercentageOfCashFeePayable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PercentageOfCashFeePayable_lbl" xml:lang="en-US"> Cash fee payable, percentage </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_LicensingTransactionFee" xlink:label="OPTI_LicensingTransactionFee"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_LicensingTransactionFee" xlink:to="OPTI_LicensingTransactionFee_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_LicensingTransactionFee_lbl" xml:lang="en-US"> License transaction fee </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PercentageOfLicensingTransactionFee" xlink:label="OPTI_PercentageOfLicensingTransactionFee"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PercentageOfLicensingTransactionFee" xlink:to="OPTI_PercentageOfLicensingTransactionFee_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PercentageOfLicensingTransactionFee_lbl" xml:lang="en-US"> License transaction fee, percentage </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostsAndExpenses" xlink:label="us-gaap_CostsAndExpenses"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostsAndExpenses" xlink:to="us-gaap_CostsAndExpenses_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostsAndExpenses_lbl" xml:lang="en-US"> Costs and expenses </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PercentageOfExecutivesCurrentYearDiscretionaryCashBonus" xlink:label="OPTI_PercentageOfExecutivesCurrentYearDiscretionaryCashBonus"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PercentageOfExecutivesCurrentYearDiscretionaryCashBonus" xlink:to="OPTI_PercentageOfExecutivesCurrentYearDiscretionaryCashBonus_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PercentageOfExecutivesCurrentYearDiscretionaryCashBonus_lbl" xml:lang="en-US"> Discretionary cash bonus, percentage </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_PercentageOfExecutivesUnvestedOptionShares" xlink:label="OPTI_PercentageOfExecutivesUnvestedOptionShares"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PercentageOfExecutivesUnvestedOptionShares" xlink:to="OPTI_PercentageOfExecutivesUnvestedOptionShares_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_PercentageOfExecutivesUnvestedOptionShares_lbl" xml:lang="en-US"> Unvested option shares, percentage </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_ReimbursementExpenses" xlink:label="OPTI_ReimbursementExpenses"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ReimbursementExpenses" xlink:to="OPTI_ReimbursementExpenses_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ReimbursementExpenses_lbl" xml:lang="en-US"> Reimbursement expenses </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl" xml:lang="en-US"> Stock issued during period shares restricted </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_lbl" xml:lang="en-US"> Stock issued during period value restricted stock award net of forfeitures </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherCommitmentDueInFourthYear" xlink:label="us-gaap_OtherCommitmentDueInFourthYear"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCommitmentDueInFourthYear" xlink:to="us-gaap_OtherCommitmentDueInFourthYear_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherCommitmentDueInFourthYear_lbl" xml:lang="en-US"> Other commitment dueIn fourth year </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xml:lang="en-US"> Ownership percentage </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_StockholdersEquityDescription" xlink:label="OPTI_StockholdersEquityDescription"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_StockholdersEquityDescription" xlink:to="OPTI_StockholdersEquityDescription_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_StockholdersEquityDescription_lbl" xml:lang="en-US"> Stockholders equity description </link:label>

<link:loc xlink:type="locator" xlink:href="opti-20220630.xsd#OPTI_FeesPercentage" xlink:label="OPTI_FeesPercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FeesPercentage" xlink:to="OPTI_FeesPercentage_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_FeesPercentage_lbl" xml:lang="en-US"> Fees percentage </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xml:lang="en-US"> Income tax benefit at federal statutory rate </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xml:lang="en-US"> State income tax benefit, net of federal benefit </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US"> Change in valuation allowance </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationDeductions" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationDeductions"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationDeductions" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationDeductions_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationDeductions_lbl" xml:lang="en-US"> Income taxes at effective tax rate </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xml:lang="en-US"> Net operating loss carryforwards </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US"> Less: Valuation allowance </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="us-gaap_DeferredTaxAssetsNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsNet" xlink:to="us-gaap_DeferredTaxAssetsNet_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsNet_lbl" xml:lang="en-US"> Net deferred tax assets </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable" xlink:label="us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable" xlink:to="us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_lbl" xml:lang="en-US"> Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems" xlink:label="us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems" xlink:to="us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_lbl" xml:lang="en-US"> Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefit" xlink:label="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefit" xlink:to="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefit_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefit_lbl" xml:lang="en-US"> Federal state and local tax, expense </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_2_lbl" xml:lang="en-US"> Equity ownership, percentage </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" xml:lang="en-US"> Schedule of Related Party Transactions, by Related Party [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="us-gaap_RelatedPartyTransactionLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_RelatedPartyTransactionLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionLineItems_lbl" xml:lang="en-US"> Related Party Transaction [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsForRent" xlink:label="us-gaap_PaymentsForRent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRent" xlink:to="us-gaap_PaymentsForRent_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsForRent_lbl" xml:lang="en-US"> Payments for rent </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RepaymentsOfRelatedPartyDebt" xlink:label="us-gaap_RepaymentsOfRelatedPartyDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfRelatedPartyDebt" xlink:to="us-gaap_RepaymentsOfRelatedPartyDebt_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepaymentsOfRelatedPartyDebt_lbl" xml:lang="en-US"> Repayments of related party debt </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_3_lbl" xml:lang="en-US"> Stock issued during period shares issued for services </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices_3_lbl" xml:lang="en-US"> Stock issued during period value issued for services </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionDueFromToRelatedParty" xlink:label="us-gaap_RelatedPartyTransactionDueFromToRelatedParty"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionDueFromToRelatedParty" xlink:to="us-gaap_RelatedPartyTransactionDueFromToRelatedParty_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionDueFromToRelatedParty_lbl" xml:lang="en-US"> Related party transaction due from to related party </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PremiumsReceivableAtCarryingValue" xlink:label="us-gaap_PremiumsReceivableAtCarryingValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PremiumsReceivableAtCarryingValue" xlink:to="us-gaap_PremiumsReceivableAtCarryingValue_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PremiumsReceivableAtCarryingValue_lbl" xml:lang="en-US"> Received insurance premium </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DueFromRelatedParties" xlink:label="us-gaap_DueFromRelatedParties"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DueFromRelatedParties" xlink:to="us-gaap_DueFromRelatedParties_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DueFromRelatedParties_lbl" xml:lang="en-US"> Due from relatedParties </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProfessionalFees" xlink:to="us-gaap_ProfessionalFees_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProfessionalFees_3_lbl" xml:lang="en-US"> Professional services, fee </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_lbl" xlink:type="arc"/>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice_lbl" xlink:type="arc"/>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xml:lang="en-US"> Expiration period </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xlink:type="arc"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTerm" xlink:to="us-gaap_DebtInstrumentTerm_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentTerm_2_lbl" xml:lang="en-US"> Loan term </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_2_lbl" xml:lang="en-US"> Annual interest, rate </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestExpenseDebt" xlink:label="us-gaap_InterestExpenseDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpenseDebt" xlink:to="us-gaap_InterestExpenseDebt_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpenseDebt_lbl" xml:lang="en-US"> Principal and interest, payments </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_3_lbl" xml:lang="en-US"> Proceeds from issuance of common stock </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_3_lbl" xml:lang="en-US"> Stock issued during period shares new issues </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_2_lbl" xml:lang="en-US"> Purchase of warrant </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="OPTI_ClassOfWarrantOrRightExpirationDate_2_lbl" xml:lang="en-US"> Class of warrant or right expiration date </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants_2_lbl" xml:lang="en-US"> Proceed from exercise of warrants </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentMaturityDateDescription" xlink:label="us-gaap_DebtInstrumentMaturityDateDescription"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDateDescription" xlink:to="us-gaap_DebtInstrumentMaturityDateDescription_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentMaturityDateDescription_lbl" xml:lang="en-US"> Debt instrument maturity date description </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_2_lbl" xml:lang="en-US"> Debt instrument interest rate stated percentage </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromContributedCapital" xlink:label="us-gaap_ProceedsFromContributedCapital"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromContributedCapital" xlink:to="us-gaap_ProceedsFromContributedCapital_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromContributedCapital_lbl" xml:lang="en-US"> Proceeds from contributed capital </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InventoryFinishedGoodsAndWorkInProcess" xlink:label="us-gaap_InventoryFinishedGoodsAndWorkInProcess"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryFinishedGoodsAndWorkInProcess" xlink:to="us-gaap_InventoryFinishedGoodsAndWorkInProcess_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryFinishedGoodsAndWorkInProcess_lbl" xml:lang="en-US"> Inventory </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InventoryValuationReserves" xlink:label="us-gaap_InventoryValuationReserves"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryValuationReserves" xlink:to="us-gaap_InventoryValuationReserves_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryValuationReserves_lbl" xml:lang="en-US"> Reserve for obsolescence </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNet" xlink:to="us-gaap_InventoryNet_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_InventoryNet_2_lbl" xml:lang="en-US"> Total inventory </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryWriteDown" xlink:to="us-gaap_InventoryWriteDown_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryWriteDown_2_lbl" xml:lang="en-US"> Inventory write down </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermNotesAndLoans" xlink:label="us-gaap_LongTermNotesAndLoans"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermNotesAndLoans" xlink:to="us-gaap_LongTermNotesAndLoans_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LongTermNotesAndLoans_lbl" xml:lang="en-US"> Loans payable </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayableCurrent" xlink:to="us-gaap_LoansPayableCurrent_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_LoansPayableCurrent_3_lbl" xml:lang="en-US"> Less current portion </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermLoansPayable" xlink:to="us-gaap_LongTermLoansPayable_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LongTermLoansPayable_2_lbl" xml:lang="en-US"> Noncurrent portion </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets [Table] </link:label>

<link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets [Line Items] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ConsultingAgreementMember" xlink:to="OPTI_ConsultingAgreementMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ConsultingAgreementMember_doc" xml:lang="en-US"> Consulting Agreement [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_SeniorConvertibleNotesPayableAndWarrantsTextBlock_doc" xml:lang="en-US"> Senior Convertible Notes Payable and Warrants [Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ConvertibleNotesPayableGross_doc" xml:lang="en-US"> Convertible notes payable gross. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_SeniorConvertiblePromissoryNotesMember_doc" xml:lang="en-US"> Senior Convertible Promissory Notes [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_KingdomBuildingConsultingAgreementMember_doc" xml:lang="en-US"> Kingdom Building Consulting Agreement [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_CommonStockPercentageOutstandingAmount_doc" xml:lang="en-US"> Common stock percentage outstanding amount. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_CommonStockPercentageAmount_doc" xml:lang="en-US"> Common stock percentage amount. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_WarrantsExercisablePricePercentage_doc" xml:lang="en-US"> Warrants exercisable price percentage. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_INTESecuritiesLLCMember" xlink:to="OPTI_INTESecuritiesLLCMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_INTESecuritiesLLCMember_doc" xml:lang="en-US"> INTE Securities LLC [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DeferredFinancingCost" xlink:to="OPTI_DeferredFinancingCost_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_DeferredFinancingCost_doc" xml:lang="en-US"> Deferred financing cost. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_MonthlyFeeForRemainingPeriod_doc" xml:lang="en-US"> Monthly fee for remaining period. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DeferredConsultingFees" xlink:to="OPTI_DeferredConsultingFees_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_DeferredConsultingFees_doc" xml:lang="en-US"> Deferred consulting fees. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrDestlerMember" xlink:to="OPTI_MrDestlerMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_MrDestlerMember_doc" xml:lang="en-US"> Mr. Destler [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_EquitySecuritiesFvNiMeasurementInputTerm_doc" xml:lang="en-US"> Equity securities FvNi measurement input term. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrHandyMember" xlink:to="OPTI_MrHandyMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_MrHandyMember_doc" xml:lang="en-US"> Mr. Handy [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrKlausnerMember" xlink:to="OPTI_MrKlausnerMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_MrKlausnerMember_doc" xml:lang="en-US"> Mr Klausner [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ExercisableWarrantPercentageAmount_doc" xml:lang="en-US"> Exercisable Warrant Percentage Amount. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ConsultantsMember" xlink:to="OPTI_ConsultantsMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ConsultantsMember_doc" xml:lang="en-US"> Consultants [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ClassOfWarrantOrRightExpirationDate_doc" xml:lang="en-US"> Warrants expiration date. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_TransferOfDepositsOnPurchaseOfEquipmentToPropertyAndEquipment_doc" xml:lang="en-US"> Transfer of deposits on purchase of equipment to property and equipment. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PercentageOfProrataSecurities_doc" xml:lang="en-US"> Percentage of prorata securities. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_PercentageOfCashFeePayable" xlink:to="OPTI_PercentageOfCashFeePayable_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PercentageOfCashFeePayable_doc" xml:lang="en-US"> Percentage of cash fee payable. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PercentageOfLicensingTransactionFee_doc" xml:lang="en-US"> Percentage of licensing transaction fee. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_LicensingTransactionFee" xlink:to="OPTI_LicensingTransactionFee_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_LicensingTransactionFee_doc" xml:lang="en-US"> Licensing Transaction Fee. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PaycheckProtectionProgramLoanMember_doc" xml:lang="en-US"> Paycheck Protection Program Loan [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PercentageOfCommonStockPurchasePrice_doc" xml:lang="en-US"> Percentage of common stock purchase price. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_LoanPayableTextBlock" xlink:to="OPTI_LoanPayableTextBlock_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_LoanPayableTextBlock_doc" xml:lang="en-US"> Loan Payable [Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PercentageOfExecutivesCurrentYearDiscretionaryCashBonus_doc" xml:lang="en-US"> Percentage of executives current year discretionary cash bonus. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PercentageOfExecutivesUnvestedOptionShares_doc" xml:lang="en-US"> Percentage of executives unvested option shares. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ReimbursementExpenses" xlink:to="OPTI_ReimbursementExpenses_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ReimbursementExpenses_doc" xml:lang="en-US"> Reimbursement expenses. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_OneCustomerMember" xlink:to="OPTI_OneCustomerMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_OneCustomerMember_doc" xml:lang="en-US"> One Customer [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PreferredStockSharesDesginated_doc" xml:lang="en-US"> Preferred stock, shares desginated. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DisperSolarLLCMember" xlink:to="OPTI_DisperSolarLLCMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_DisperSolarLLCMember_doc" xml:lang="en-US"> Disper Solar LLC [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EarnoutPaymentsDescription" xlink:to="OPTI_EarnoutPaymentsDescription_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_EarnoutPaymentsDescription_doc" xml:lang="en-US"> Earnout Payments, description. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EarnoutPaymentsMember" xlink:to="OPTI_EarnoutPaymentsMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_EarnoutPaymentsMember_doc" xml:lang="en-US"> Earnout Payments [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationAwardTrancheFourMember_doc" xml:lang="en-US"> Share Based Compensation Award Tranche Four [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PercentageOfConsiderationReceived_doc" xml:lang="en-US"> Percentage of consideration received. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrBoothMember" xlink:to="OPTI_MrBoothMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_MrBoothMember_doc" xml:lang="en-US"> Mr. Booth [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ConcentrationRiskPercentage_doc" xml:lang="en-US"> Concentration risk percentage. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber_doc" xml:lang="en-US"> Warrants, Balance exercisable. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageGrantDateFairValue_doc" xml:lang="en-US"> Weighted Average Exercise Price, Balance outstanding. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGrantedWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGrantedWeightedAverageGrantDateFairValue_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGrantedWeightedAverageGrantDateFairValue_doc" xml:lang="en-US"> Weighted Average Exercise Price, granted. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisedWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisedWeightedAverageGrantDateFairValue_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisedWeightedAverageGrantDateFairValue_doc" xml:lang="en-US"> Weighted Average Exercise Price, exercised. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirationsWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirationsWeightedAverageGrantDateFairValue_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirationsWeightedAverageGrantDateFairValue_doc" xml:lang="en-US"> Weighted Average Exercise Price, expired or forfeited. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue_doc" xml:lang="en-US"> Weighted average grant date fair value, per share. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_WarrantExercisePriceOneMember_doc" xml:lang="en-US"> Warrant Exercise Price One [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRights1_doc" xml:lang="en-US"> Weighted Average Exercise Price. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_WarrantsAndRightsExercisableOutstanding_doc" xml:lang="en-US"> Warrants and rights exercisable. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ClassOfWarrantOrRightExercisableWeightedAverageExercisePriceOfWarrantsOrRights1_doc" xml:lang="en-US"> Weighted average exercise price of warrants or rights1. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_AaronDanksMember" xlink:to="OPTI_AaronDanksMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_AaronDanksMember_doc" xml:lang="en-US"> Aaron Danks [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTermWarrantsOutstandingAndExercisable_doc" xml:lang="en-US"> Share based compensation arrangement by share based payment award options exercisable weighted average remaining contractual term warrants outstanding and exercisable. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValuePerShare" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValuePerShare_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValuePerShare_doc" xml:lang="en-US"> Share based compensation arrangement by share based payment award options vested and expected to vest outstanding aggregate intrinsic value per share. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_CommonStockSharesPurchased" xlink:to="OPTI_CommonStockSharesPurchased_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_CommonStockSharesPurchased_doc" xml:lang="en-US"> Common stock shares purchased. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_WarrantsToPurchaseCommonStock_doc" xml:lang="en-US"> Warrants to purchase common stock. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PercentageOfWarrantsExercisable_doc" xml:lang="en-US"> Percentage of warrants exercisable. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_AdvisoryBoardAgreementMember_doc" xml:lang="en-US"> Advisory Board Agreement [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_TwoThousandAndSixteenEquityIncentivePlanMember_doc" xml:lang="en-US"> 2016 Equity Incentive Plan [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_DescriptionOfIncreaseInSalaryPercentage_doc" xml:lang="en-US"> Description of increase in salary percentage. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EmploymentAgreementMember" xlink:to="OPTI_EmploymentAgreementMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_EmploymentAgreementMember_doc" xml:lang="en-US"> Employment Agreement [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_PatentPurchaseObligationCurrent_doc" xml:lang="en-US"> Patent purchase obligation. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_GainOnForgivenessOfSbaPppLoan_doc" xml:lang="en-US"> Gain on forgiveness of sba ppp loan. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_AdjustmentsToAdditionalPaidInCapitalVestedOptionsAndWarrantIssuedForService_doc" xml:lang="en-US"> Amount of increase in additional paid in capital (APIC) resulting from the issuance of vested options and warrants for service. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_StockIssuedDuringPeriodValueCommonSharesAndWarrantsIssuedInPrivateOfferings_doc" xml:lang="en-US"> Stock issued during period value common shares and warrants issued in private offerings. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_StockIssuedDuringPeriodSharesCommonSharesAndWarrantsIssuedInPrivateOfferings_doc" xml:lang="en-US"> Stock issued during period shares common shares and warrants issued in private offerings. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_AmortizationOfIntangibleAsset_doc" xml:lang="en-US"> Amortization of intangible asset. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_FairValueOfVestedOptionsAndWarrants_doc" xml:lang="en-US"> Fair value of vested options and warrants. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_DepositsToAcquirePropertyPlantAndEquipment_doc" xml:lang="en-US"> Deposits on purchase of equipment. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_RepaymentOfPatentPurchaseObligation_doc" xml:lang="en-US"> Repayment of patent purchase obligation. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_FairValueOfWarrantsRecordedAsDebtDiscount_doc" xml:lang="en-US"> Fair value of warrants recorded as a debt discount. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_RepaymentsOfDeferredOfferingCosts_doc" xml:lang="en-US"> Repayments of deferred offering costs. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FinancingCosts" xlink:to="OPTI_FinancingCosts_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_FinancingCosts_doc" xml:lang="en-US"> Financing costs. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_DeferredOfferingCostsPolicyTextBlock_doc" xml:lang="en-US"> Deferred Offering Costs [Policy Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ScheduleOfEstimatedUsefulLivesOfPropertyAndEquipmentTableTextBlock_doc" xml:lang="en-US"> Schedule of Estimated Useful Lives of Property and Equipment [Table Text Block] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_OptionsMember" xlink:to="OPTI_OptionsMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_OptionsMember_doc" xml:lang="en-US"> Options [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_SeniorConvertibleNotesMember_doc" xml:lang="en-US"> Senior Convertible Notes [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_SeriesAPreferredStocksMember_doc" xml:lang="en-US"> Series A Preferred Stocks [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_EarnoutAndRoyaltyObligationsDisclosureTextBlock_doc" xml:lang="en-US"> Earnout And Royalty Obligations Disclosure [Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_FairValueOfVestedRestrictedStockUnits_doc" xml:lang="en-US"> Fair value of vested restricted stock units. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_InvestorWarrantsMember" xlink:to="OPTI_InvestorWarrantsMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_InvestorWarrantsMember_doc" xml:lang="en-US"> Investor Warrants [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ProceedsFromExerciseOfWarrants_doc" xml:lang="en-US"> Proceeds from exercise of warrants. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_StockholdersEquityDescription_doc" xml:lang="en-US"> Stockholders equity description. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ReclassificationOfVendorDepositsToInventory_doc" xml:lang="en-US"> Reclassification of vendor deposits to inventory. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ReclassificationOfVendorDepositsToPropertyAndEquipment_doc" xml:lang="en-US"> Reclassification of vendor deposits to property and equipment. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FeesPercentage" xlink:to="OPTI_FeesPercentage_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_FeesPercentage_doc" xml:lang="en-US"> Fees percentage. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ScheduleOfShareBasedCompensationWarrantsByExercisePriceRangeTextBlock_doc" xml:lang="en-US"> Schedule of Share Based Compensation Warrants By Exercise Price Range [TableText Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_SeniorConvertibleNoteHoldersMember_doc" xml:lang="en-US"> Senior Convertible Note Holders [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_WarrantExercisePriceTwoMember_doc" xml:lang="en-US"> Warrant Exercise Price Two [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_WarrantExercisePriceThreeMember_doc" xml:lang="en-US"> Warrant Exercise Price Three [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_WarrantExercisePriceFourMember_doc" xml:lang="en-US"> Warrant Exercise Price Four [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_RestrictedStockUnitsMember" xlink:to="OPTI_RestrictedStockUnitsMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_RestrictedStockUnitsMember_doc" xml:lang="en-US"> Restricted Stock Units [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_TwoCustomerMember" xlink:to="OPTI_TwoCustomerMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_TwoCustomerMember_doc" xml:lang="en-US"> Two Customer [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ThreeCustomerMember" xlink:to="OPTI_ThreeCustomerMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ThreeCustomerMember_doc" xml:lang="en-US"> Three Customer [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FourCustomerMember" xlink:to="OPTI_FourCustomerMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_FourCustomerMember_doc" xml:lang="en-US"> Four Customer [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_FiveCustomerMember" xlink:to="OPTI_FiveCustomerMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_FiveCustomerMember_doc" xml:lang="en-US"> Five Customer [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_NoCustomerMember" xlink:to="OPTI_NoCustomerMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_NoCustomerMember_doc" xml:lang="en-US"> No Customer [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_DeferredOfferingCost" xlink:to="OPTI_DeferredOfferingCost_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_DeferredOfferingCost_doc" xml:lang="en-US"> Deferred offering cost. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_InvestorsMember" xlink:to="OPTI_InvestorsMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_InvestorsMember_doc" xml:lang="en-US"> Investors [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_StockOptionToPurchaseCommonStock_doc" xml:lang="en-US"> Stock option to purchase common stock. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EquityIncentivePlanMember" xlink:to="OPTI_EquityIncentivePlanMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_EquityIncentivePlanMember_doc" xml:lang="en-US"> Equity Incentive Plan [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_StockOptionDescription" xlink:to="OPTI_StockOptionDescription_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_StockOptionDescription_doc" xml:lang="en-US"> Stock option description. </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ConvertiblePromissoryNotesMember_doc" xml:lang="en-US"> Convertible Promissory Notes [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsTerm" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsTerm_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsTerm_doc" xml:lang="en-US"> Share based compensation arrangement by share based payment award options term. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_SharehildersMember" xlink:to="OPTI_SharehildersMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_SharehildersMember_doc" xml:lang="en-US"> Sharehilders [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_CommonStockWarrantShare" xlink:to="OPTI_CommonStockWarrantShare_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_CommonStockWarrantShare_doc" xml:lang="en-US"> Common stock warrant share. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_KingdomBuildingIncMember" xlink:to="OPTI_KingdomBuildingIncMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_KingdomBuildingIncMember_doc" xml:lang="en-US"> Kingdom Building Inc [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_TerminationAgreementMember" xlink:to="OPTI_TerminationAgreementMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_TerminationAgreementMember_doc" xml:lang="en-US"> Termination Agreement [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_TwoThousandTwentyTwoStockIncentivePlanMember_doc" xml:lang="en-US"> Two Thousand Twenty Two Stock Incentive Plan [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonVested" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonVested_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonVested_doc" xml:lang="en-US"> Share Based Compensation Arrangement By Share Based Payment Award Options Non Vested. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_EmployementAgreementMember" xlink:to="OPTI_EmployementAgreementMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_EmployementAgreementMember_doc" xml:lang="en-US"> Employement Agreement [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_MrHandysMember" xlink:to="OPTI_MrHandysMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_MrHandysMember_doc" xml:lang="en-US"> Mr. Handys [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_StockIncentivePlanMember" xlink:to="OPTI_StockIncentivePlanMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_StockIncentivePlanMember_doc" xml:lang="en-US"> Stock Incentive Plan [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrants" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrants_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrants_doc" xml:lang="en-US"> Share based compensation arrangement by share based payment award options grants. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ConsultantsAgreementMember" xlink:to="OPTI_ConsultantsAgreementMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ConsultantsAgreementMember_doc" xml:lang="en-US"> Consultants Agreement [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_TwoThousandSixteenStockIncentivePlanMember_doc" xml:lang="en-US"> Two Thousand Sixteen Stock Incentive Plan [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_RepaymentsAndProceedsFromRelatedPartyDebt_doc" xml:lang="en-US"> Repayments and proceeds from related party debt. </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_WarrantHolderMember" xlink:to="OPTI_WarrantHolderMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_WarrantHolderMember_doc" xml:lang="en-US"> Warrant Holder [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ExercisePriceOneMember" xlink:to="OPTI_ExercisePriceOneMember_doc" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_ExercisePriceOneMember_doc" xml:lang="en-US"> Exercise Price One [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_JanuaryOneTwoThousandTwentyTwoMember_doc" xml:lang="en-US"> January 1, 2022 [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_JanuaryOneTwoThousandTwentyThreeMember_doc" xml:lang="en-US"> January 1, 2023 [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_JulyOneTwoThousandTwentyTwoMember_doc" xml:lang="en-US"> July 1, 2022 [Member] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OPTI_JulyOneTwoThousandTwentyThreeMember_doc" xml:lang="en-US"> July 1, 2023 [Member] </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsCurrent_2_lbl" xml:lang="en-US"> Assets, Current </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Assets_2_lbl" xml:lang="en-US"> Assets </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrent_2_lbl" xml:lang="en-US"> Liabilities, Current </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Liabilities_2_lbl" xml:lang="en-US"> Liabilities </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_5_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquity_5_lbl" xml:lang="en-US"> Stockholders' Equity Attributable to Parent </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_2_lbl" xml:lang="en-US"> Liabilities and Equity </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpenses_2_lbl" xml:lang="en-US"> Operating Expenses </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingIncomeLoss_2_lbl" xml:lang="en-US"> Operating Income (Loss) </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpense_2_lbl" xml:lang="en-US"> Interest Expense </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonoperatingIncomeExpense_2_lbl" xml:lang="en-US"> Nonoperating Income (Expense) </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesOutstanding" xlink:to="us-gaap_SharesOutstanding_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesOutstanding_3_lbl" xml:lang="en-US"> Shares, Outstanding </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_AmortizationOfIntangibleAsset_3_lbl" xml:lang="en-US"> AmortizationOfIntangibleAsset </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_FairValueOfVestedRestrictedStockUnits_3_lbl" xml:lang="en-US"> FairValueOfVestedRestrictedStockUnits </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_2_lbl" xml:lang="en-US"> Increase (Decrease) in Accounts Receivable </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInInventories_2_lbl" xml:lang="en-US"> Increase (Decrease) in Inventories </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_2_lbl" xml:lang="en-US"> Increase (Decrease) in Prepaid Expense and Other Assets </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_2_lbl" xml:lang="en-US"> Increase (Decrease) in Accounts Payable and Accrued Liabilities </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_3_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Operating Activities </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_2_lbl" xml:lang="en-US"> Payments to Acquire Property, Plant, and Equipment </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_DepositsToAcquirePropertyPlantAndEquipment_3_lbl" xml:lang="en-US"> DepositsToAcquirePropertyPlantAndEquipment </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_2_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Investing Activities </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_RepaymentsOfDeferredOfferingCosts_3_lbl" xml:lang="en-US"> RepaymentsOfDeferredOfferingCosts </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepaymentsOfShortTermDebt_2_lbl" xml:lang="en-US"> Repayments of Short-Term Debt </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_RepaymentOfPatentPurchaseObligation_3_lbl" xml:lang="en-US"> RepaymentOfPatentPurchaseObligation </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_RepaymentsAndProceedsFromRelatedPartyDebt_3_lbl" xml:lang="en-US"> RepaymentsAndProceedsFromRelatedPartyDebt </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_2_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Financing Activities </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_2_lbl" xml:lang="en-US"> Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_3_lbl" xml:lang="en-US"> Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_2_lbl" xml:lang="en-US"> Stockholders' Equity Note Disclosure [Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_2_lbl" xml:lang="en-US"> Commitments and Contingencies Disclosure [Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryDisclosureTextBlock_2_lbl" xml:lang="en-US"> Inventory Disclosure [Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryPolicyTextBlock_2_lbl" xml:lang="en-US"> Inventory, Policy [Policy Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_2_lbl" xml:lang="en-US"> Property, Plant and Equipment, Policy [Policy Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_2_lbl" xml:lang="en-US"> Income Tax, Policy [Policy Text Block] </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ConcentrationRiskPercentage_3_lbl" xml:lang="en-US"> ConcentrationRiskPercentage </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedLiabilitiesCurrent_2_lbl" xml:lang="en-US"> Accrued Liabilities, Current </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LegalFees" xlink:to="us-gaap_LegalFees_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LegalFees_2_lbl" xml:lang="en-US"> Legal Fees </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayable" xlink:to="us-gaap_NotesPayable_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotesPayable_2_lbl" xml:lang="en-US"> Notes Payable </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayable" xlink:to="us-gaap_LoansPayable_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansPayable_2_lbl" xml:lang="en-US"> Loans Payable </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_3_lbl" xml:lang="en-US"> Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageGrantDateFairValue_4_lbl" xml:lang="en-US"> ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageGrantDateFairValue </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised_2_lbl" xml:lang="en-US"> Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Exercised </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations_3_lbl" xml:lang="en-US"> Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Forfeitures and Expirations </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber_3_lbl" xml:lang="en-US"> ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableNumber </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue" xlink:to="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue_3_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OPTI_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue_3_lbl" xml:lang="en-US"> ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageGrantDateFairValue </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_2_lbl" xml:lang="en-US"> Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_2_lbl" xml:lang="en-US"> Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_2_lbl" xml:lang="en-US"> Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_2_lbl" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_2_lbl" xml:lang="en-US"> Deferred Tax Assets, Valuation Allowance </link:label>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryFinishedGoodsAndWorkInProcess_2_lbl" xml:lang="en-US"> Inventory, Finished Goods and Work in Process, Gross </link:label>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermNotesAndLoans" xlink:to="us-gaap_LongTermNotesAndLoans_2_lbl" xlink:type="arc"/>

<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermNotesAndLoans_2_lbl" xml:lang="en-US"> Notes and Loans, Noncurrent </link:label>

</link:labelLink>

</link:linkbase>

11 Subsequent Filings that Reference this Filing

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 1/11/24  Opti-Harvest, Inc.                S-1/A                 73:15M                                    M2 Compliance LLC/FA
12/29/23  Opti-Harvest, Inc.                S-1/A                 78:15M                                    M2 Compliance LLC/FA
11/20/23  Opti-Harvest, Inc.                10-Q        9/30/23   57:5.6M                                   M2 Compliance LLC/FA
 8/21/23  Opti-Harvest, Inc.                10-Q        6/30/23   57:5.5M                                   M2 Compliance LLC/FA
 6/26/23  Opti-Harvest, Inc.                S-1                   74:14M                                    M2 Compliance LLC/FA
 6/21/23  Opti-Harvest, Inc.                POS AM                74:14M                                    M2 Compliance LLC/FA
 5/18/23  Opti-Harvest, Inc.                10-Q        3/31/23   57:4.7M                                   M2 Compliance LLC/FA
 4/17/23  Opti-Harvest, Inc.                10-K       12/31/22   68:7M                                     M2 Compliance LLC/FA
 2/08/23  Opti-Harvest, Inc.                S-1/A                  2:96K                                    M2 Compliance LLC/FA
 2/03/23  Opti-Harvest, Inc.                S-1/A                 80:13M                                    M2 Compliance LLC/FA
 1/13/23  Opti-Harvest, Inc.                S-1/A                 78:13M                                    M2 Compliance LLC/FA

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