Note 15 - Stock-based Compensation - Schedule of Outstanding Unvested Stock Options (Details) - $ / shares	12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020
Nonvested balance (in shares)	3,891,207	6,797,471	3,310,600
Nonvested, Weighted Average Grant-Date Fair Value (in dollars per share)	$ 0.66	$ 0.46	$ 0.59
Granted, number of stock options (in shares)	1,279,692	959,588	6,163,900
Granted, Weighted Average Grant-Date Fair Value (in dollars per share)	$ 2.45	$ 1.30	$ 0.45
Vested (in shares)	(2,984,745)	(3,865,852)	(2,590,154)
Vested, Weighted Average Grant-Date Fair Value (in dollars per share)	$ 0.59	$ 0.47	$ 0.60
Cancelled/Forfeited (in shares)			(86,875)
Cancelled/Forfeited, Weighted Average Grant-Date Fair Value (in dollars per share)			$ 0.43
Nonvested balance (in shares)	2,186,154	3,891,207	6,797,471
Nonvested, Weighted Average Grant-Date Fair Value (in dollars per share)	$ 1.79	$ 0.66	$ 0.46