STOCK-BASED COMPENSATION (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	May 31, 2023	May 31, 2022	May 31, 2021
Net stock-based compensation	$ 2,748	$ 2,923	$ 1,101
Effect on net loss per share, basic	$ 0.10	$ 0.11	$ 0.05
Effect on net loss per share, diluted	$ 0.09	$ 0.11	$ 0.05
Cost of Sales
Total stock-based compensation	$ 331	$ 234	$ 70
Selling, General and Administrative
Total stock-based compensation	1,711	1,721	816
Research and Development
Total stock-based compensation	$ 706	$ 968	$ 215