Net Loss Per Share Attributable to Common Stockholders - Summary of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net loss	$ (14,592)	$ (3,384)	$ (51,830)	$ (4,837)
Denominator:
Weighted-average common shares outstanding	58,056,176	9,434,321	27,375,777	6,044,175
Less: weighted-average unvested restricted shares and shares subject to repurchase	(5,286,260)	(6,052,203)	(6,707,217)	(4,135,416)
Weighted-average shares used to compute basic and diluted net loss per share attributable to common stockholders	52,769,916	3,382,118	20,668,560	1,908,759
Net loss per share attributable to common stockholders—basic and diluted	$ (0.28)	$ (1.00)	$ (2.51)	$ (2.53)