7. Income Taxes (Details - Unrecognized tax positions) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2021	Apr. 30, 2020
Income Tax Disclosure [Abstract]
Unrecognized tax positions, beginning of year	$ 0	$ 0
Gross increase - prior period tax positions	1,600	0
Unrecognized tax positions, end of year	$ 1,600	$ 0

Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319

Name:	us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration