6. INCOME TAXES - Unrecognized tax benefits (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Mar. 31, 2022
INCOME TAXES
Unrecognized tax benefits, current	$ 0		$ 0		$ 0
Deferred tax assets unrecognized tax benefit	3,600,000		3,600,000
Provision (benefit) for income taxes	37,000	$ 42,000	97,000	$ (130,000)
Income (loss) before income taxes	$ (3,191,000)	$ (4,525,000)	$ (7,107,000)	$ (8,906,000)
Effective annual income tax rate (as a percentage)			(1.69%)	0.49%