Note 9 - Stock Based Compensation - Summary of Stock Option Activity (Details) - $ / shares	9 Months Ended	12 Months Ended
	Jun. 30, 2022	Sep. 30, 2021	Jun. 30, 2021
Outstanding (in shares)	2,702,500
Outstanding, weighted average exercise price (in dollars per share)	$ 4.42
Outstanding, weighted average remaining contractual term (Year)	3 years 4 months 20 days	5 years 1 month 17 days
Granted (in shares)	1,030,000
Granted, weighted average exercise price (in dollars per share)	$ 0.99
Forfeited (in shares)	(930,000)
Forfeited, weighted average exercise price (in dollars per share)	$ 3.59
Outstanding (in shares)	2,802,500	2,702,500
Outstanding, weighted average exercise price (in dollars per share)	$ 3.43	$ 4.42
Exercisable (in shares)			1,822,500
Exercisable, weighted average exercise price (in dollars per share)			$ 4.19
Exercisable at June 30, 2022 (Year)	4 years 7 months 17 days