Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summary of Warrant Activity (Details)

v3.22.0.1
Stockholders' Equity - Summary of Warrant Activity (Details) - Warrant - USD ($)
9 Months Ended
Jan. 31, 2022
Apr. 30, 2021
Jan. 31, 2022
Number of Shares      
Balance Outstanding, April 30, 2021 (in shares)     374,174
Granted (in shares)     75,000
Warrants exercised (in shares)     0
Surrendered (in shares)     0
Expired (in shares)     0
Balance Outstanding, January 31, 2022 (in shares) 449,174 374,174 449,174
Exercisable, January 31, 2022 (in shares) 424,174   424,174
Weighted Average Exercise Price      
Balance Outstanding, April 30, 2021 (in dollars per share)     $ 6.37
Granted (in dollars per share)     6.23
Exercised (in dollars per share)     0
Surrendered (in dollars per share)     0
Expired (in dollars per share)     0
Balance Outstanding, January 31, 2022 (in dollars per share) $ 6.35 $ 6.37 6.35
Exercisable, January 31, 2022 (in dollars per share) $ 6.31   $ 6.31
Weighted Average Remaining Contractual Term      
Weighted Average Remaining Contractual Term, Outstanding 1 year 8 months 15 days 1 year 10 months 24 days  
Weighted Average Remaining Contractual Term, Granted     4 years 6 months 18 days
Weighted Average Remaining Contractual Term, Exercisable 1 year 6 months 18 days    
Aggregate Intrinsic Value      
Average Intrinsic Value $ 0 $ 0 $ 0
Aggregate Intrinsic Value, Exercisable $ 0   $ 0