2. Summary of Significant Accounting Policies (Details - Revenue) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020
Revenues	$ 21,806	$ 13,585	$ 68,262	$ 47,152
Manufacturing Revenue [Member]
Revenues	17,895	11,525	60,407	40,422
Process Development Revenue [Member]
Revenues	$ 3,911	$ 2,060	$ 7,855	$ 6,730