Note 12 - Stock-based Compensation - Summary of Stock Options Outstanding and Exercisable (Details) - $ / shares	3 Months Ended
	Oct. 31, 2023	Jul. 31, 2023
Options Outstanding (in shares)	7,518,042	8,326,983
Options outstanding, weighted average exercise price (in dollars per share)	$ 1.94	$ 1.92
Options outstanding, weighted average remaining contractual term (Year)	7 years 2 months 23 days
Options exercisable (in shares)	5,842,639
Options exercisable, weighted average exercise price (in dollars per share)	$ 1.47
Options exercisable, weighted average remaining contractual term (Year)	6 years 8 months 12 days
Exercise Price Range 1 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 0.8
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 0.99
Options Outstanding (in shares)	3,013,687
Options outstanding, weighted average exercise price (in dollars per share)	$ 0.92
Options outstanding, weighted average remaining contractual term (Year)	6 years 2 months 23 days
Options exercisable (in shares)	3,013,687
Options exercisable, weighted average exercise price (in dollars per share)	$ 0.92
Options exercisable, weighted average remaining contractual term (Year)	6 years 2 months 23 days
Exercise Price Range 2 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 1
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 1.99
Options Outstanding (in shares)	1,390,500
Options outstanding, weighted average exercise price (in dollars per share)	$ 1.11
Options outstanding, weighted average remaining contractual term (Year)	6 years 5 months 19 days
Options exercisable (in shares)	1,390,500
Options exercisable, weighted average exercise price (in dollars per share)	$ 1.11
Options exercisable, weighted average remaining contractual term (Year)	6 years 5 months 19 days
Exercise Price Range 3 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 2
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 2.99
Options Outstanding (in shares)	715,344
Options outstanding, weighted average exercise price (in dollars per share)	$ 2.24
Options outstanding, weighted average remaining contractual term (Year)	7 years 6 months 25 days
Options exercisable (in shares)	715,344
Options exercisable, weighted average exercise price (in dollars per share)	$ 2.24
Options exercisable, weighted average remaining contractual term (Year)	7 years 6 months 25 days
Exercise Price Range 4 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 3
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 3.99
Options Outstanding (in shares)	2,376,011
Options outstanding, weighted average exercise price (in dollars per share)	$ 3.6
Options outstanding, weighted average remaining contractual term (Year)	8 years 10 months 2 days
Options exercisable (in shares)	720,608
Options exercisable, weighted average exercise price (in dollars per share)	$ 3.7
Options exercisable, weighted average remaining contractual term (Year)	8 years 3 months 7 days
Exercise Price Range 5 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 4
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 4.23
Options Outstanding (in shares)	10,000
Options outstanding, weighted average exercise price (in dollars per share)	$ 4.48
Options outstanding, weighted average remaining contractual term (Year)	9 years 5 months 1 day
Options exercisable (in shares)	2,500
Options exercisable, weighted average exercise price (in dollars per share)	$ 4.23
Options exercisable, weighted average remaining contractual term (Year)	8 years 11 months 23 days
Exercise Price Range 6 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 5
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 5.2
Options Outstanding (in shares)	12,500
Options outstanding, weighted average exercise price (in dollars per share)	$ 5.16
Options outstanding, weighted average remaining contractual term (Year)	9 years 10 months 28 days
Options exercisable (in shares)	0
Options exercisable, weighted average exercise price (in dollars per share)	$ 0