Stock Based Compensation (Details Narrative)				1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 01, 2021 $ / shares shares	Oct. 30, 2020 $ / shares shares	May 08, 2018 $ / shares shares	Oct. 31, 2018 Days $ / shares shares	Apr. 30, 2021 USD ($) $ / shares shares	Apr. 30, 2020 USD ($) shares	Apr. 30, 2021 USD ($) $ / shares shares	Apr. 30, 2020 USD ($) shares	Mar. 25, 2021 $ / shares shares
Stock option compensation to employees and directors | $							$ 1,755,638	$ 2,019,211
Weighted average exercise per share | $ / shares							$ 2.58
Shares options, granted
Stock options exercised, shares							44,000
Stock options exercised | $					$ 189,380	$ 75,250	$ 293,604	$ 103,730
Proceeds from stock plans | $							$ 3,000	15,452
Warrants [Member]
Vesting period		5 months
Warrant expiration date		Oct. 30, 2025
Warrants purchase of common stock shares		60,000
Warrant exercise price | $ / shares		$ 2.06			$ 5.03		$ 5.03
Consulting expense | $					$ 38,000		$ 96,000
Warrants to purchase common stock					500,000		500,000
Warrants maturity date					Nov. 30, 2021		Nov. 30, 2021
Warrants issued
Warrants [Member] | Public Offering [Member]
Warrant exercise price | $ / shares									$ 6.5625
Warrants to purchase common stock									300,000
Warrants maturity date									Mar. 22, 2026
Stock Option [Member]
Option to purchase common stock					77,571	77,571	107,451	107,451
Shares withheld on a cashless exercise					7,937	7,937	7,937	7,937
Stock options exercised, shares					25,000	25,000	43,900	43,900
Stock options exercised | $					$ 189,000	$ 75,000	$ 294,000	$ 104,000
2018 Plan [Member]
Weighted average exercise per share | $ / shares							$ 3.81
Shares options, granted							1,380,000	800,000
Stock options exercised, shares							33,888
Shares available for future grants					1,757,937		1,757,937
2018 Plan [Member] | Stock Option [Member] | Subsequent Event [Member]
Vesting period	1 year
Option to purchase common stock	2,990,000
Shares options, granted	100,000
Stock options, vested, number of shares	30,000
Stock options award, description	Our Lead Independent Director, our Chairman, President and Chief Executive Officer and our Chief Operating Officer and Chief Financial Officer were awarded options for 200,000 shares, 500,000 shares and 100,000 shares, respectively, that vest over three years.
First Tranche [Member]
Option to purchase common stock				500,000
Weighted average exercise per share | $ / shares				$ 5.00
Consecutive trading days | Days				20
Minimum [Member] | 2018 Plan [Member] | Stock Option [Member] | Subsequent Event [Member]
Weighted average exercise per share | $ / shares	$ 5.00
Maximum [Member] | 2018 Plan [Member] | Stock Option [Member] | Subsequent Event [Member]
Weighted average exercise per share | $ / shares	$ 8.00
Shares options, granted	2,000,000
Employees and Directors [Member]
Stock option compensation to employees and directors | $					$ 881,000	1,055,000	$ 1,756,000	$ 2,019,000
Employees and Directors [Member] | Minimum [Member]
Vesting period							1 year
Employees and Directors [Member] | Maximum [Member]
Vesting period							4 years
Chairman, President and Chief Executive Officer [Member]
Option to purchase common stock			1,500,000
Expiration date			May 31, 2021
Chairman, President and Chief Executive Officer [Member] | 2018 Plan [Member] | Restricted Stock [Member]
Option to purchase common stock			1,500,000
Weighted average exercise per share | $ / shares			$ 11.00
Expiration date			May 31, 2021
Chairman, President and Chief Executive Officer [Member] | Minimum [Member]
Weighted average exercise per share | $ / shares			$ 5.00
Service period			3 months
Chairman, President and Chief Executive Officer [Member] | Maximum [Member]
Weighted average exercise per share | $ / shares			$ 8.00
Service period			7 months
Consultants [Member]
Stock option compensation to employees and directors | $					$ 132,000	$ 55,000	$ 186,000	$ 112,000
Employees and Consultants [Member] | 2018 Plan [Member]
Shares options, granted					250,000	0	1,380,000	800,000
Employees and Consultants [Member] | Minimum [Member] | 2018 Plan [Member]
Exercise price | $ / shares					$ 2.83		$ 2.83
Employees and Consultants [Member] | Maximum [Member] | 2018 Plan [Member]
Exercise price | $ / shares					$ 5.30		$ 5.30
Employees [Member] | Employee Stock Purchase Plan [Member]
Option to purchase common stock							1,634	9,618
Purchase price of common stock percentage							85.00%
Proceeds from stock plans | $							$ 3,000	$ 15,000