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Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details)
9 Months Ended
Jan. 31, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Dividend rate 0.00%
Expected volatility 146.10%
Minimum [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Risk-free interest rate 0.07%
Expected life (in years) 6 months
Maximum [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Risk-free interest rate 0.08%
Expected life (in years) 9 months 18 days