| STOCK OPTIONS AND WARRANTS (Tables)
 | 3 Months Ended | 
| Jul. 31, 2022 | 
|---|
| Share-Based Payment Arrangement [Abstract] |  | 
| Assumptions for options | 
  
    | Assumptions for options |  |  |  |  |  |  |  
    |  |  | Three Months Ended July 31, |  |  
    |  |  | 2022 |  |  | 2021 |  |  
    | Risk-free interest rate |  |  | 2.9% |  |  |  | 0.87% |  |  
    | Expected volatility |  |  | 139% |  |  |  | 113% |  |  
    | Expected lives (years) |  |  | 2.5 |  |  |  | 2.5 |  |  
    | Expected dividend yield |  |  | 0.00% |  |  |  | 0.00% |  |  | 
| Schedule of stock option activity | 
  
    | Schedule of stock option activity |  |  |  |  |  |  |  |  |  
    | Options |  | Weighted Average Exercise Price per Share |  |  | Weighted Average Grant Date Fair Value per Share |  |  
    | Outstanding, April 30, 2022 |  |  | 40,900 |  |  | $ | 53.05 |  |  
    | Issued |  |  | 1,002 |  |  |  | 2.27 |  |  
    | Forfeited |  |  | (3,633 | ) |  |  | 104.62 |  |  
    | Outstanding, July 31, 2022 |  |  | 38,269 |  |  | $ | 46.83 |  |  
    | Exercisable, July 31, 2022 |  |  | 35,769 |  |  | $ | 49.92 |  |  
    | Vested and expected to vest |  |  | 38,269 |  |  | $ | 46.83 |  |  | 
| Unvested stock option activity | 
  
    | Unvested stock option activity |  |  |  |  |  |  |  
    |  |  | Options |  |  | Weighted Average
 Grant Date
 Fair Value
 per Share
 |  |  
    |  |  |  |  |  |  |  |  
    | Unvested, April 30, 2022 |  |  | 4,000 |  |  | $ | – |  |  
    | Issued |  |  | 1,002 |  |  |  | 2.27 |  |  
    | Vested |  |  | (2,502 | ) |  |  | – |  |  
    | Forfeited |  |  | – |  |  |  | – |  |  
    | Unvested, July 31, 2022 |  |  | 2,500 |  |  | $ | 2.50 |  |  | 
| Schedule of options by exercise price | 
  
    | Schedule of options by exercise price |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Exercise Price |  |  | Number of Options
 Outstanding
 |  |  | Weighted Average
 Remaining
 Contractual Life
 (Years) of
 Outstanding
 Options
 |  |  | Weighted Average
 Exercisable
 Price Per Share
 |  |  | Number of Options
 Exercisable
 |  |  | Weighted Average Exercise Price Per Share
 of Exercisable
 Options
 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | $ | 82.95 |  |  |  | 333 |  |  |  | 0.10 |  |  | $ | 82.95 |  |  |  | 333 |  |  | $ | 82.95 |  |  
    | $ | 83.70 |  |  |  | 6,000 |  |  |  | 0.25 |  |  | $ | 83.70 |  |  |  | 6,000 |  |  | $ | 83.70 |  |  
    | $ | 80.10 |  |  |  | 800 |  |  |  | 1.10 |  |  | $ | 80.10 |  |  |  | 800 |  |  | $ | 80.10 |  |  
    | $ | 80.85 |  |  |  | 667 |  |  |  | 0.38 |  |  | $ | 80.85 |  |  |  | 667 |  |  | $ | 80.85 |  |  
    | $ | 102.45 |  |  |  | 333 |  |  |  | 0.46 |  |  | $ | 102.45 |  |  |  | 333 |  |  | $ | 102.45 |  |  
    | $ | 97.35 |  |  |  | 333 |  |  |  | 0.60 |  |  | $ | 97.35 |  |  |  | 333 |  |  | $ | 97.35 |  |  
    | $ | 74.25 |  |  |  | 6,000 |  |  |  | 0.98 |  |  | $ | 74.25 |  |  |  | 6,000 |  |  | $ | 74.25 |  |  
    | $ | 57.00 |  |  |  | 800 |  |  |  | 2.15 |  |  | $ | 57.00 |  |  |  | 800 |  |  | $ | 57.00 |  |  
    | $ | 60.60 |  |  |  | 667 |  |  |  | 0.88 |  |  | $ | 60.60 |  |  |  | 667 |  |  | $ | 60.60 |  |  
    | $ | 55.50 |  |  |  | 333 |  |  |  | 0.95 |  |  | $ | 55.50 |  |  |  | 333 |  |  | $ | 55.50 |  |  
    | $ | 51.00 |  |  |  | 333 |  |  |  | 1.10 |  |  | $ | 51.00 |  |  |  | 333 |  |  | $ | 51.00 |  |  
    | $ | 61.20 |  |  |  | 6,000 |  |  |  | 1.46 |  |  | $ | 61.20 |  |  |  | 6,000 |  |  | $ | 61.20 |  |  
    | $ | 36.00 |  |  |  | 667 |  |  |  | 1.38 |  |  | $ | 36.00 |  |  |  | 667 |  |  | $ | 36.00 |  |  
    | $ | 37.05 |  |  |  | 333 |  |  |  | 1.46 |  |  | $ | 37.05 |  |  |  | 333 |  |  | $ | 37.05 |  |  
    | $ | 15.75 |  |  |  | 333 |  |  |  | 1.60 |  |  | $ | 15.70 |  |  |  | 333 |  |  | $ | 15.70 |  |  
    | $ | 10.05 |  |  |  | 6,000 |  |  |  | 2.05 |  |  | $ | 10.05 |  |  |  | 6,000 |  |  | $ | 10.05 |  |  
    | $ | 26.55 |  |  |  | 667 |  |  |  | 1.88 |  |  | $ | 26.55 |  |  |  | 667 |  |  | $ | 26.55 |  |  
    | $ | 16.20 |  |  |  | 334 |  |  |  | 1.96 |  |  | $ | 16.20 |  |  |  | 334 |  |  | $ | 16.20 |  |  
    | $ | 3.19 |  |  |  | 334 |  |  |  | 2.10 |  |  | $ | 3.19 |  |  |  | 334 |  |  | $ | 3.19 |  |  
    | $ | 2.50 |  |  |  | 6,000 |  |  |  | 2.65 |  |  | $ | 2.50 |  |  |  | 3,500 |  |  | $ | 2.50 |  |  
    | $ | 2.29 |  |  |  | 668 |  |  |  | 2.38 |  |  | $ | 2.29 |  |  |  | 668 |  |  | $ | 2.29 |  |  
    | $ | 2.24 |  |  |  | 334 |  |  |  | 2.46 |  |  | $ | 2.24 |  |  |  | 334 |  |  | $ | 2.24 |  |  
    |  | Total |  |  |  | 38,269 |  |  |  | 1.19 |  |  | $ | 46.83 |  |  |  | 35,769 |  |  | $ | 46.83 |  |  | 
| Schedule of warrant activity | 
  
    | Schedule of warrant activity |  |  |  |  |  |  |  
    |  |  | Warrants |  |  | WeightedAverage
 Exercise Price
 Per Share |  |  
    | Outstanding, April 30, 2022 |  |  | 10,772,736 |  |  | $ | 4.59 |  |  
    | Issued |  |  | - |  |  |  | – |  |  
    | Exercised |  |  | (880,000 | ) |  |  | – |  |  
    | Expired |  |  | (1,889 | ) |  |  | – |  |  
    | Outstanding, July 31, 2022 |  |  | 9,890,847 |  |  |  | – |  |  
    | Exercisable, July 31, 2022 |  |  | 9,890,847 |  |  | $ | 4.99 |  |  | 
| Schedule of warrants outstanding and exercisable | 
  
    | Schedule of warrants outstanding and exercisable |  |  |  |  |  |  |  |  |  |  
    | Exercise Prices |  | Number of Warrant Shares
 Exercisable at
 July 31, 2022
 |  |  | Weighted Average
 Remaining
 Contractual
 Life Years
 |  |  | Weighted Average
 Exercise Price Per Share
 |  |  
    |  |  |  |  |  |  |  |  |  |  |  
    | $4.25 |  |  | 1,506,141 |  |  |  | 4.03 |  |  |  |  |  |  
    | $5.3125 |  |  | 264,706 |  |  |  | 4.03 |  |  |  |  |  |  
    | $5.00 |  |  | 7,000,000 |  |  |  | 4.07 |  |  |  |  |  |  
    | $6.25 |  |  | 1,050,000 |  |  |  | 4.05 |  |  |  |  |  |  
    | $0.001 |  |  | 70,000 |  |  |  | – |  |  |  |  |  |  
    |  |  |  | 9,890,847 |  |  |  | 4.06 |  |  | $ | 4.99 |  |  |