UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance (in shares) at Apr. 30, 2021		13,414,066
Beginning balance at Apr. 30, 2021	$ 7,428	$ 13	$ 79,945	$ (72,530)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	280		280
Issuance of common stock on exercise of stock options (in shares)		1,000
Issuance of common stock on exercise of stock options	2		2
Net income (loss)	(172)			(172)
Ending balance (in shares) at Jul. 31, 2021		13,415,066
Ending balance at Jul. 31, 2021	7,538	$ 13	80,227	(72,702)
Beginning balance (in shares) at Apr. 30, 2021		13,414,066
Beginning balance at Apr. 30, 2021	7,428	$ 13	79,945	(72,530)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	892
Ending balance (in shares) at Jan. 31, 2022		13,517,941
Ending balance at Jan. 31, 2022	9,236	$ 14	80,860	(71,638)
Beginning balance (in shares) at Jul. 31, 2021		13,415,066
Beginning balance at Jul. 31, 2021	7,538	$ 13	80,227	(72,702)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	134		134
Issuance of common stock on exercise of stock options (in shares)		81,078
Issuance of common stock on exercise of stock options	122	$ 1	121
Net income (loss)	277			277
Ending balance (in shares) at Oct. 31, 2021		13,496,144
Ending balance at Oct. 31, 2021	8,071	$ 14	80,482	(72,425)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	310		310
Issuance of common stock on exercise of stock options (in shares)		21,797
Issuance of common stock on exercise of stock options	68		68
Net income (loss)	787			787
Ending balance (in shares) at Jan. 31, 2022		13,517,941
Ending balance at Jan. 31, 2022	$ 9,236	$ 14	80,860	(71,638)
Beginning balance (in shares) at Apr. 30, 2022	13,558,650	13,522,441
Beginning balance at Apr. 30, 2022	$ 9,096	$ 14	81,064	(71,982)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	206		206
Net income (loss)	(319)			(319)
Ending balance (in shares) at Jul. 31, 2022		13,522,441
Ending balance at Jul. 31, 2022	$ 8,983	$ 14	81,270	(72,301)
Beginning balance (in shares) at Apr. 30, 2022	13,558,650	13,522,441
Beginning balance at Apr. 30, 2022	$ 9,096	$ 14	81,064	(71,982)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (2,774)
Ending balance (in shares) at Jan. 31, 2023	13,558,650	13,558,650
Ending balance at Jan. 31, 2023	$ 7,064	$ 14	81,806	(74,756)
Beginning balance (in shares) at Jul. 31, 2022		13,522,441
Beginning balance at Jul. 31, 2022	8,983	$ 14	81,270	(72,301)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	119		119
Issuance of common stock on exercise of stock options (in shares)		36,209
Issuance of common stock on exercise of stock options	86		86
Net income (loss)	(16)			(16)
Ending balance (in shares) at Oct. 31, 2022		13,558,650
Ending balance at Oct. 31, 2022	9,172	$ 14	81,475	(72,317)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	331		331
Net income (loss)	$ (2,439)			(2,439)
Ending balance (in shares) at Jan. 31, 2023	13,558,650	13,558,650
Ending balance at Jan. 31, 2023	$ 7,064	$ 14	$ 81,806	$ (74,756)