2. Summary of Significant Accounting Policies (Details - Useful life)	12 Months Ended
	Apr. 30, 2021
Leasehold Improvements [Member]
Useful lives of property and equipment	Shorter of estimated useful life or lease term
Laboratory and Manufacturing Equipment [Member]
Useful lives of property and equipment	5-10 years
Computer Equipment and software [Member]
Useful lives of property and equipment	3-5 years
Furniture, fixtures and office equipment [Member]
Useful lives of property and equipment	5-10 years