SIGNIFICANT ACCOUNTING POLICIES (Details) - Options Activity - Share-based Payment Arrangement, Option [Member]	9 Months Ended
	Feb. 28, 2021 $ / shares shares
SIGNIFICANT ACCOUNTING POLICIES (Details) - Options Activity [Line Items]
Options Outstanding, Shares | shares	1,789,251
Option Outstanding, Exercise Price Weighted Average | $ / shares	$ 2.75
Option Granted, Shares | shares	407,616
Option Granted, Exercise Price Weighted Average | $ / shares	$ 6.82
Option Exercised, Shares | shares	(81,750)
Option Exercised, Exercise Price Weighted Average | $ / shares	$ 1.20
Option Cancelled or expired, Shares | shares	(35,751)
Option Cancelled or expired, Exercise Price Weighted Average | $ / shares	$ 4.26
Options Outstanding, Shares | shares	2,079,366
Option Outstanding, Exercise Price Weighted Average | $ / shares	$ 3.58