XML 91 R76.htm IDEA: XBRL DOCUMENT v3.21.2
Income Taxes - Narrative (Details) - USD ($)
Apr. 30, 2021
Apr. 30, 2020
Apr. 30, 2019
Income Tax Disclosure [Abstract]      
Valuation allowance $ 14,776,048 $ 12,399,948 $ 10,051,034
Net operating loss carry forwards 61,100,000    
Operating loss carryforwards subject to expiration $ 28,200,000