Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021
BELGIUM
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	$ 0	$ 36
BRAZIL
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	368	106
FRANCE
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	0	123
CHINA
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	0	215
RUSSIAN FEDERATION
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	23	94
GERMANY
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	17	31
ITALY
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	35	27
KOREA, REPUBLIC OF
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	7	82
SINGAPORE
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	0	32
TAIWAN
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	0	101
UNITED KINGDOM
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	198	261
Other Countries [Member]
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	233	315
Foreign Revenue [Member]
Segment Information (Details) - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Line Items]
Revenues	$ 881	$ 1,423