Note 14 - Related-party Transactions (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2023	Apr. 30, 2022
Director David Hayden [Member] \| Consulting Fees [Member]
Related Party Transaction, Amounts of Transaction	$ 135	$ 135
Edgar Law Firm LLC [Member]
Related Party Transaction, Amounts of Transaction	113	214
Compensation Expense, Excluding Cost of Good and Service Sold	331	484
Chief Executive Officer [Member]
Accrued Liabilities, Current	244	482
Wayne Stewart [Member]
Compensation Expense, Excluding Cost of Good and Service Sold	303	292
Jeff Shinkle [Member]
Compensation Expense, Excluding Cost of Good and Service Sold	$ 254	$ 247

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of expense for salary, wage, profit sharing; incentive and equity-based compensation; and other employee benefit. Other employee benefit expense includes, but is not limited to, service component of net periodic benefit cost for defined benefit plan. Excludes compensation cost in cost of good and service sold.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(b)(4))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

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- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-3

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