NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss	$ 59,351	$ 58,763	$ 15,572
Preferred stock accretion and cumulative dividends	8,241	11,934	9,749
Total loss attributable to common stockholders	$ 67,592	$ 70,697	$ 25,321
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	71,073,052	24,939,901	22,754,499
Net loss per share attributable to common stockholders, basic and diluted	$ 0.95	$ 2.83	$ 1.11