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Summary of Significant Accounting Policies (Details Narrative) - USD ($)	6 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Apr. 30, 2021	Aug. 31, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 72,630,000		$ 83,028,000
Revenue remaining performance obligation	$ 300,000
Revenue remaining performance obligation, percentage	100.00%
Performance obligation revenue of next twelve months	$ 300,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4,928,474	5,540,469
Santander Bank [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Letters of credit issued amount	$ 258,000
Santander Bank [Member] | Letter 2 [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Letters of credit issued amount	64,000
Santander Bank [Member] | Letter 2 [Member] | August 2020 [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Letters of credit outstanding, amount				$ 323,000
Foreign Financial Institutions [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash and Cash Equivalents, at Carrying Value	32,000
Restricted Cash and Security Agreements [Member] | Santander Bank [Member] | Letter of Credit [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deposits	157,000
Restricted Cash and Security Agreements [Member] | Santander Bank [Member] | Letter 1 [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Letters of credit outstanding, amount	126,000
Restricted Cash and Security Agreements [Member] | Santander Bank [Member] | Letter 2 [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Letters of credit outstanding, amount	$ 645,000

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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