Quarterly report pursuant to Section 13 or 15(d)

changes in warrants outstanding (Details)

v3.21.4
changes in warrants outstanding (Details) - Warrants Outstanding 1 [Member] - USD ($)
6 Months Ended 12 Months Ended
Oct. 31, 2021
Apr. 30, 2021
Apr. 30, 2020
Class of Warrant or Right [Line Items]      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number 1,539,999 873,332
Share-based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price $ 3.38 $ 1.50
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value $ 2,387,731 $ 2,218,263
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross 733,333 1,074,998  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value $ 5.45 $ 1.50  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (66,666) (201,666)  
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price $ 1.50 $ 1.50  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term 4 years 4 months 17 days 4 years 7 months 13 days