Note 15 - Income Taxes - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Federal statutory income tax rate	21.00%	21.00%
State income taxes, net of federal benefit	(0.80%)	2.10%
Permanent differences	(4.30%)	11.90%
Contingent derivative expense	0.00%	0.50%
Change in value of convertible debt	(1.00%)	(2.50%)
Expiration of tax carryovers	(28.90%)	0.00%
Change in valuation allowance	14.00%	(33.00%)
Provision for income taxes	0.00%	0.00%