| 5. COMMON STOCK TRANSACTIONS (Details - Nonvested Option activity) - Restricted Stock [Member] - $ / shares | 12 Months Ended | |
|---|---|---|
| Apr. 30, 2021 | Apr. 30, 2020 | |
| Options Outstanding | ||
| Beginning balance | 3,067 | 3,067 | 
| Granted | 6,733 | 10,867 | 
| Vested | (6,867) | (10,867) | 
| Forfeited | 0 | 0 | 
| Ending balance | 2,933 | 3,067 | 
| Weighted Average Grant Date Fair Value | ||
| Beginning balance | $ 82.76 | $ 74.50 | 
| Granted | 17.01 | 75.98 | 
| Vested | 39.61 | 73.65 | 
| Forfeited | ||
| Ending balance | $ 10.05 | $ 82.76 | 
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- Definition Weighted Average Grant Date Fair Value [Abstract] No definition available. 
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- Definition Net number of non-option equity instruments granted to participants. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available. 
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- Definition Number of non-vested options outstanding. No definition available. 
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- Definition Number of non-vested options forfeited. No definition available. 
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- Definition Weighted average grant-date fair value of non-vested options forfeited. No definition available. 
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- Definition Weighted average grant-date fair value of non-vested options outstanding. No definition available. 
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- Definition Number of options vested. No definition available. 
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- Definition Weighted average grant-date fair value of options vested. No definition available. 
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- Details 
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