Quarterly report pursuant to Section 13 or 15(d)

Assumptions used to determine fair value of derivative warrant liability

v3.21.2
Assumptions used to determine fair value of derivative warrant liability - Derivative Warrant Liability [Member]
3 Months Ended
Jul. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum 0.52%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum 0.69%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate
[custom:SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1Minimum] 4 years 2 months 1 day
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term 4 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum 211.02%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum 219.34%