Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Apr. 30, 2020
Payables And Accruals [Abstract]
Accrued sales allowances	$ 2,931	$ 2,441
Accrued freight	2,466	1,646
Accrued commissions	1,578	954
Accrued taxes other than income	1,052	197
Accrued warranty	717	336
Accrued professional fees	701	787
Accrued other	245	540
Accrued employee benefits	153	754
Total accrued expenses	$ 9,843	$ 7,655