Note 8 - Shareholders' Equity - Fair Value Assumptions of Stock Options (Details)	12 Months Ended
Sep. 30, 2022 $ / shares	Sep. 30, 2021 $ / shares
Measurement Input, Risk Free Interest Rate [Member]
Measurement Input	0.0000
Minimum [Member] \| Measurement Input, Risk Free Interest Rate [Member]
Measurement Input	0.0039
Maximum [Member] \| Measurement Input, Risk Free Interest Rate [Member]
Measurement Input		0.0089
Share-Based Payment Arrangement, Option [Member]
Weighted average exercise price (in dollars per share)	$ 0.99	$ 3.91
Share-Based Payment Arrangement, Option [Member] \| Measurement Input, Price Volatility [Member]
Measurement Input	0.0000	1.0342
Share-Based Payment Arrangement, Option [Member] \| Measurement Input, Expected Term [Member]
Measurement Input	0	2.75
Share-Based Payment Arrangement, Option [Member] \| Minimum [Member]
Risk free interest rate	2.56%	0.16%
Volatility	101.23%	100.72%
Expected term (in years) (Year)	2 years 6 months	2 years 6 months
Measurement Input	0
Share-Based Payment Arrangement, Option [Member] \| Maximum [Member]
Risk free interest rate	2.97%	0.85%
Volatility	103.98%	105.43%
Expected term (in years) (Year)	5 years 6 months	5 years 6 months
Measurement Input		3.74

Agreed-upon price for the exchange of the underlying asset relating to the share-based payment award.

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iv)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

Rate of weighted-average expected volatility for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(ii)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

Value of input used to measure outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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