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Summary of Significant Accounting Policies (Details Narrative) - USD ($)	3 Months Ended		9 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020	Aug. 31, 2020	Apr. 30, 2020
Cash and cash equivalents	$ 79,801,000		$ 79,801,000			$ 10,002,000
Revenue remaining performance obligation	500,000		$ 500,000
Revenue remaining performance obligation, percentage			89.00%
Performance obligation revenue of next twelve months	$ 400,000		$ 400,000
Antidilutive securities excluded from computation of earnings per share, shares	5,221,258	5,565,462	5,221,258	5,565,462
Santander Bank, N.A. [Member] | Letter 2 [Member]
Letters of credit issued, amount	$ 64,547		$ 64,547
Santander Bank, N.A. [Member] | Letter 2 [Member] | August 2020 [Member]
Letters of credit outstanding, amount					$ 322,734
Foreign Financial Institutions [Member]
Cash and cash equivalents	300,000		300,000
Restricted Cash and Security Agreements [Member] | Santander Bank, N.A. [Member] | Letter 1 [Member]
Letters of credit outstanding, amount	125,690		$ 125,690
Line of credit expiration period			May 31, 2021
Restricted Cash and Security Agreements [Member] | Santander Bank, N.A. [Member] | Letter 2 [Member]
Letters of credit outstanding, amount	$ 645,467		$ 645,467

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