Note 12 - Stock-based Compensation - Summary of Stock Options Outstanding and Exercisable (Details) - $ / shares	9 Months Ended
	Apr. 30, 2024	Jan. 31, 2024	Oct. 31, 2023	Jul. 31, 2023
Options Outstanding (in shares)	6,249,671	6,649,539	7,518,042	8,326,983
Options outstanding, weighted average exercise price (in dollars per share)	$ 2.07	$ 2.01	$ 1.94	$ 1.92
Options outstanding, weighted average remaining contractual term (Year)	6 years 11 months 23 days
Options exercisable (in shares)	4,991,925
Options exercisable, weighted average exercise price (in dollars per share)	$ 1.67
Options exercisable, weighted average remaining contractual term (Year)	6 years 6 months 3 days
Exercise Price Range 1 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 0.91
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 0.99
Options Outstanding (in shares)	2,140,500
Options outstanding, weighted average exercise price (in dollars per share)	$ 0.92
Options outstanding, weighted average remaining contractual term (Year)	5 years 9 months 29 days
Options exercisable (in shares)	2,140,500
Options exercisable, weighted average exercise price (in dollars per share)	$ 0.92
Options exercisable, weighted average remaining contractual term (Year)	5 years 9 months 29 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)	1,325,000
Options outstanding, weighted average exercise price (in dollars per share)	$ 1.1
Options outstanding, weighted average remaining contractual term (Year)	6 years 2 months 15 days
Options exercisable (in shares)	1,325,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 1.1
Options exercisable, weighted average remaining contractual term (Year)	6 years 2 months 15 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)	537,149
Options outstanding, weighted average exercise price (in dollars per share)	$ 2.26
Options outstanding, weighted average remaining contractual term (Year)	7 years 2 months 4 days
Options exercisable (in shares)	537,149
Options exercisable, weighted average exercise price (in dollars per share)	$ 2.26
Options exercisable, weighted average remaining contractual term (Year)	7 years 2 months 4 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)	2,176,879
Options outstanding, weighted average exercise price (in dollars per share)	$ 3.61
Options outstanding, weighted average remaining contractual term (Year)	8 years 5 months 4 days
Options exercisable (in shares)	982,401
Options exercisable, weighted average exercise price (in dollars per share)	$ 3.71
Options exercisable, weighted average remaining contractual term (Year)	8 years 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)	$ 4.99
Options Outstanding (in shares)	7,500
Options outstanding, weighted average exercise price (in dollars per share)	$ 4.56
Options outstanding, weighted average remaining contractual term (Year)	9 years 21 days
Options exercisable (in shares)	2,500
Options exercisable, weighted average exercise price (in dollars per share)	$ 4.48
Options exercisable, weighted average remaining contractual term (Year)	8 years 11 months 1 day
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)	$ 5.99
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 5 months 1 day
Options exercisable (in shares)	3,125
Options exercisable, weighted average exercise price (in dollars per share)	$ 5.16
Options exercisable, weighted average remaining contractual term (Year)	9 years 5 months 1 day
Exercise Price Range 7 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 6
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 6.99
Options Outstanding (in shares)	40,143
Options outstanding, weighted average exercise price (in dollars per share)	$ 6.7
Options outstanding, weighted average remaining contractual term (Year)	9 years 10 months 20 days
Options exercisable (in shares)	0
Exercise Price Range 8 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 7
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 7.63
Options Outstanding (in shares)	10,000
Options outstanding, weighted average exercise price (in dollars per share)	$ 7.63
Options outstanding, weighted average remaining contractual term (Year)	9 years 8 months 23 days
Options exercisable (in shares)	1,250
Options exercisable, weighted average exercise price (in dollars per share)	$ 7.63
Options exercisable, weighted average remaining contractual term (Year)	9 years 8 months 23 days