CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Series A	Series B-1	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning balance, Shares at Dec. 31, 2019		10,819,843	8,344,034
Beginning balance at Dec. 31, 2019		$ 100,695	$ 81,384
Beginning balance, Shares at Dec. 31, 2019				3,927,803
Beginning balance at Dec. 31, 2019	$ (64,891)				$ 1,421	$ (66,197)	$ (115)
Issuance of common stock upon exercise of stock options	18				18
Issuance of common stock upon exercise of stock options, shares				13,672
Issuance of Series A stock upon exercise of Series A warrants		$ 487
Issuance of Series A stock upon exercise of Series A warrants, shares		37,555
Stock-based compensation	331				331
Vesting of early exercised options from existing exercises	63				63
Other comprehensive income	567						567
Net loss	(20,029)					(20,029)
Ending balance, Shares at Mar. 31, 2020		10,857,397	8,344,034
Ending balance at Mar. 31, 2020		$ 101,182	$ 81,384
Ending balance, Shares at Mar. 31, 2020				3,941,476
Ending balance at Mar. 31, 2020	(83,941)				1,833	(86,226)	452
Beginning balance, Shares at Dec. 31, 2020				38,120,606
Beginning balance at Dec. 31, 2020	220,039			$ 4	394,963	(174,740)	(188)
Issuance of common stock upon exercise of stock options	96				96
Issuance of common stock upon exercise of stock options, shares				26,599
Stock-based compensation	2,756				2,756
Vesting of early exercised common stock options	42				42
Other comprehensive income	(39)						(39)
Net loss	(27,674)					(27,674)
Ending balance, Shares at Mar. 31, 2021				38,147,205
Ending balance at Mar. 31, 2021	$ 195,220			$ 4	$ 397,857	$ (202,414)	$ (227)