Stockholders' Equity (Deficit) - Summary of Warrant Outstanding and Exercisable Warrants (Details) - $ / shares
 12 Months Ended
Apr. 30, 2020
Apr. 30, 2019
Apr. 30, 2018
Warrant One [Member]      
Number of Warrants Outstanding 22,000,000    
Weighted Average Remaining Contractual life (in years) 4 years 8 months 12 days    
Weighted Average Exercise Price, Outstanding $ 0.0001    
Number of Warrants Exercisable 22,000,000    
Weighted Average Exercise Price, Exercisable $ 0.0001    
Warrant Two [Member]      
Number of Warrants Outstanding 2,180,000    
Weighted Average Remaining Contractual life (in years) 3 years 1 month 6 days    
Weighted Average Exercise Price, Outstanding $ 0.04    
Number of Warrants Exercisable 2,180,000    
Weighted Average Exercise Price, Exercisable $ 0.04    
Warrant Three [Member]      
Number of Warrants Outstanding 2,270,600    
Weighted Average Remaining Contractual life (in years) 10 months 25 days    
Weighted Average Exercise Price, Outstanding $ 0.25    
Number of Warrants Exercisable 2,270,600    
Weighted Average Exercise Price, Exercisable $ 0.25    
Warrant Four [Member]      
Number of Warrants Outstanding 100,000    
Weighted Average Remaining Contractual life (in years) 1 year 10 months 25 days    
Weighted Average Exercise Price, Outstanding $ 3.00    
Number of Warrants Exercisable 100,000    
Weighted Average Exercise Price, Exercisable $ 3.00    
Warrant Five [Member]      
Number of Warrants Outstanding 333,333    
Weighted Average Remaining Contractual life (in years) 2 years 4 months 24 days    
Weighted Average Exercise Price, Outstanding $ 0.15    
Number of Warrants Exercisable 333,333    
Weighted Average Exercise Price, Exercisable $ 0.15    
Warrant [Member]      
Number of Warrants Outstanding 26,883,933    
Weighted Average Remaining Contractual life (in years) 2 years 4 months 24 days 8 years 8 months 12 days  
Weighted Average Exercise Price, Outstanding $ 0.04 $ 0.24 $ 0.04
Number of Warrants Exercisable 26,883,933