Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Income Tax Disclosure [Abstract]
Federal net operating loss carryforwards	$ 43,788	$ 40,338
Foreign net operating loss carryforwards	2,059	2,061
State operating loss carryforwards	1,578	968
Federal and New Jersey research and development tax credits	5,143	4,167
Stock compensation	662	429
Accrued expenses	474	79
Capitalized section 174 research & development	1,453
Leases	448	207
Other	76	142
Net deferred tax assets before valuation allowance	55,681	48,391
Valuation allowance	(54,644)	(47,597)
Deferred tax assets	1,037	794
Lease liabilities	448	203
Intangibles	792	794
Net deferred tax liabilities	$ (203)	$ (203)