Note 9 - Warrants - Schedule of Equity-Classified Warrants (Details) - $ / shares	6 Months Ended
	Mar. 31, 2025	Oct. 01, 2024
Granted, warrants (in shares)	0
Granted, warrant, weighted average exercise price (in dollars per share)	$ 0
Exercised, warrants (in shares)	0
Exercised, warrant, weighted average exercise price (in dollars per share)	$ 0
Forfeited, warrants (in shares)	(267)
Forfeited, warrant, weighted average exercise price (in dollars per share)	$ 1,024.38
Exercisable, warrants (in shares)	5,901
Exercisable, warrant, weighted average exercise price (in dollars per share)	$ 208.75
Warrants to Purchase Common Stock [Member]
Outstanding, warrants (in shares)	6,168
Outstanding, warrant, weighted average exercise price (in dollars per share)	$ 233.99
Outstanding, warrant, contractual term (Year)	4 months 6 days	3 years 5 months 1 day
Outstanding, warrants (in shares)	5,901
Outstanding, warrant, weighted average exercise price (in dollars per share)	$ 208.75
Exercisable, warrants (in shares)	5,901
Exercisable, warrant, weighted average exercise price (in dollars per share)	$ 208.75