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Common Stock (Details Narrative) - USD ($) |  |  |  |  | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | ---
Oct. 24, 2019 | Apr. 08, 2019 | Jan. 07, 2019 | Aug. 13, 2018 | Apr. 30, 2020 | Apr. 30, 2020 | Apr. 30, 2019
Common stock, shares authorized |  |  |  |  | 100,000,000 | 100,000,000 | 100,000,000
Common stock, par value |  |  |  |  | $ 0.001 | $ 0.001 | $ 0.001
Common stock, shares issued |  |  |  |  | 12,939,420 | 12,939,420 | 5,425,517
Number of common stock shares sold |  | 1,542,000 |  |  |  |  |
Aggregate offering price |  | $ 15,700,000 |  |  |  |  |
Pre-funded Warrants [Member] |  |  |  |  |  |  |
Warrant to purchase shares common stock |  | 3,385,680 |  |  |  |  |
Over-Allotment Option [Member] |  |  |  |  |  |  |
Number of common stock shares sold |  | 642,000 |  |  |  |  |
Stock Purchase Agreement [Member] | Aspire Capital Fund, LLC [Member] |  |  |  |  |  |  |
Aggregate purchase of common stock | $ 10,000,000 |  |  | $ 10,000,000 |  |  |
Percentage of outstanding common stock limit for shareholder approval |  |  |  | 19.99% |  |  |
Number of shares can be issued based upon outstanding percentage |  |  |  | 183,591 |  |  |
Common stock issued for commitment fee |  |  |  | 21,429 |  |  |
Number of common stock shares sold | 162,162 |  |  |  |  |  |
Value of common stock shares sold, net of issuance costs | $ 949,259 |  |  |  |  |  |
Sale of stock, price per share | $ 5.85 |  |  |  |  |  |
Stock Purchase Agreement [Member] | Aspire Capital Fund, LLC [Member] | December 20, 2019 [Member] |  |  |  |  |  |  |
Stock issued for new issue, shares | 5,400,000 |  |  |  |  |  |
Stock Purchase Agreement [Member] | Aspire Capital Fund, LLC [Member] | Maximum [Member] |  |  |  |  |  |  |
Percentage of outstanding common stock limit for shareholder approval | 19.99% |  |  |  |  |  |
Number of shares can be issued based upon outstanding percentage | 1,219,010 |  |  |  |  |  |
Common stock issued for commitment fee | 194,805 |  |  |  |  |  |
Sale of stock, price per share |  |  |  |  | $ 0.82 | $ 0.82 |
Stock issued for new issue, shares |  |  |  |  | 1,399,205 | 1,399,205 |
Stock issued for new issue, value |  |  |  |  | $ 1,100,000 | $ 1,100,000 |
2019 ATM Facility [Member] | A.G.P./ Alliance Global Partners [Member] |  |  |  |  |  |  |
Number of common stock shares sold |  |  |  |  |  | 5,101,405 |
Value of common stock shares sold, net of issuance costs |  |  |  |  |  | $ 3,800,000 |
Sale of stock, price per share |  |  |  |  | $ 0.74 | $ 0.74 |
Aggregate offering price |  |  | $ 25,000,000 |  |  |  |
Payment of sales commission |  |  |  |  |  | $ 122,530 |
Securities Purchase Agreement [Member] |  |  |  |  |  |  |
Warrant to purchase shares common stock |  | 4,927,680 |  |  |  |  |

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