Stockholders'/Members' Equity (Deficit) - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Jun. 30, 2021	Jul. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Beginning balances	$ 230,653	$ (74,521)	$ 230,653	$ (74,521)	$ 209,974	$ 178,023		$ (63,837)	$ (56,011)
Proceeds from issuance of common stock			75,001	0
Payment of initial public offering costs			$ 0	(120)
Common stock, shares issued (in shares)	35,190,428		35,190,428		32,171,560		6,220,050
Stock-based compensation	$ 4,366	$ 0	$ 21,307	$ 0
Total number of common shares reserved for issuance	7,437,939		7,437,939		6,122,181
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent			15.00%
Common Stock, Capital Shares Reserved for Future Issuance	7,437,939		7,437,939		6,122,181
Common stock authorized for issuance under plan	350,000,000		350,000,000		350,000,000
Equity Option
Class Of Stock [Line Items]
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount	$ 14,300		$ 14,300
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			3 years 2 months 12 days
Share-based Payment Arrangement, Plan Modification, Number of Shares			7,747
Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value			$ 27.42
Restricted Stock Units
Class Of Stock [Line Items]
Common stock, shares issued (in shares)	2,553,198		2,553,198		2,535,143
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount	$ 19,900		$ 19,900
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			2 years 4 months 24 days
Share-based Payment Arrangement, Plan Modification, Number of Shares			138,461
Private Placement of Common Stock [Member]
Class Of Stock [Line Items]
Proceeds from the Private Placement, net of underwriting discounts and commissions and other offering costs			$ 71,000
Sale of stock price per share	$ 28.00		$ 28.00
Common stock, shares issued (in shares)	2,678,600		2,678,600
2020 Equity Incentive Plan [Member]
Class Of Stock [Line Items]
Common shares authorized for issuance	6,226,540		6,226,540		4,939,678
Shares available for awards, description			On January 1st of each year, commencing with the first January 1st following the effective date of the 2020 Plan, the shares authorized for issuance under the 2020 Plan shall be increased by a number of shares equal to the lesser of 4% of the total number of shares outstanding on the immediately preceding December 31st and such lesser number of shares determined by the Company’s board of directors.
Vesting percentage			25.00%
Vesting period			36 months
Vesting terms, description			Awards under the 2020 Plan generally vest at 25% one year from the vesting commencement date and ratably each month thereafter for a period of 36 months, subject to continuous service.
Employees Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Common stock, shares issued (in shares)	5,280		5,280
Total number of common shares reserved for issuance	828,713		828,713		464,829
Common Stock, Capital Shares Reserved for Future Issuance	828,713		828,713		464,829
Common stock authorized for issuance under plan	833,993		833,993		464,829
Share Based Compensation Arrangement By Share Based Payment Award Percentage Of Outstanding Stock Maximum			1.00%
Maximum annual increase of shares of common stock authorized for issuance			929,658
Class B Common Stock
Class Of Stock [Line Items]
Beginning balances	$ 0		$ 0		$ 0	$ 0
Common stock, shares issued (in shares)	1,492,059		1,492,059		1,492,059
Vesting period			4 years
Common stock authorized for issuance under plan	15,368,569		15,368,569		15,368,569
IPO [Member]
Class Of Stock [Line Items]
Sale of stock issued in transaction					12,075,000
Sale of stock price per share					$ 18.00
Payment of initial public offering costs					$ 198,300
Common stock, shares issued (in shares)					13,876,510
IPO [Member] | Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Convertible Preferred Stock, Shares Issued upon Conversion					199,791,519
IPO [Member] | Class B Common Stock
Class Of Stock [Line Items]
Common stock, shares issued (in shares)					1,492,059