Basis of presentation and description of business - Consolidated Statements of Stockholders' Equity (Details) - USD ($) $ in Thousands			3 Months Ended				9 Months Ended
		Jul. 24, 2020	Sep. 30, 2021		Sep. 30, 2020		Sep. 30, 2021		Sep. 30, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	[1]		$ 803,959		$ 492,070		$ 811,014		$ 500,722
Exercise of stock options	[1]		1,507		82		8,570		185
Share‑based compensation	[1]		15,836		2,328		22,774		3,903
Net loss			(30,383)	[1]	(5,388)	[1]	(51,439)	[1]	(15,718)	[2]
Ending balance	[1]		$ 746,769		810,318		$ 746,769		810,318
IPO
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (shares)		13,500,000
Issuance of common stock	[1]				318,993				318,993
Private placement
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (shares)		85,880
Issuance of common stock		$ 2,200			$ 2,233	[1]			$ 2,233	[1]
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)			118,249,912		102,862,404		116,992,472		102,843,612
Beginning balance			$ 118		$ 103		$ 117		$ 103
Exercise of stock options (in shares)			269,416		15,000		1,526,856		33,792
Exercise of stock options			$ 1				$ 2
Ending balance (in shares)			119,027,104		116,463,284		119,027,104		116,463,284
Ending balance			$ 119		$ 117		$ 119		$ 117
Common Stock | IPO
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (shares)					13,500,000				13,500,000
Issuance of common stock					$ 14				$ 14
Common Stock | Private placement
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (shares)					85,880				85,880
Additional Paid‑In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			917,116		$ 570,434		903,116		$ 568,756
Exercise of stock options			1,506		82		8,568		185
Share‑based compensation			15,836		2,328		22,774		3,903
Ending balance			898,428		894,056		898,428		894,056
Additional Paid‑In Capital | IPO
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					318,979				318,979
Additional Paid‑In Capital | Private placement
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					2,233				2,233
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	[1]		(113,275)		(78,467)		(92,219)		(68,137)
Net loss	[1]		(30,383)		(5,388)		(51,439)		(15,718)
Ending balance	[1]		$ (143,658)		(83,855)		(143,658)		(83,855)
As Previously Reported
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance					496,843		815,481		503,878
Exercise of stock options					82				185
Share‑based compensation					2,328				3,903
Net loss					(5,093)				(13,806)
Ending balance					815,386				815,386
As Previously Reported | IPO
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					318,993				318,993
As Previously Reported | Private placement
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					$ 2,233				$ 2,233
As Previously Reported | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)					102,862,404				102,843,612
Beginning balance					$ 103				$ 103
Exercise of stock options (in shares)					15,000				33,792
Ending balance (in shares)					116,463,284				116,463,284
Ending balance					$ 117				$ 117
As Previously Reported | Common Stock | IPO
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (shares)					13,500,000				13,500,000
Issuance of common stock					$ 14				$ 14
As Previously Reported | Common Stock | Private placement
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (shares)					85,880				85,880
As Previously Reported | Additional Paid‑In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance					$ 570,434				$ 568,756
Exercise of stock options					82				185
Share‑based compensation					2,328				3,903
Ending balance					894,056				894,056
As Previously Reported | Additional Paid‑In Capital | IPO
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					318,979				318,979
As Previously Reported | Additional Paid‑In Capital | Private placement
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					2,233				2,233
As Previously Reported | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance					(73,694)				(64,981)
Net loss					(5,093)				(13,806)
Ending balance					(78,787)				(78,787)
Adjustments | Commissions
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance					(3,753)		(4,708)		(2,830)
Exercise of stock options					0				0
Share‑based compensation					0				0
Net loss					(369)				(1,292)
Ending balance					(4,122)				(4,122)
Adjustments | Commissions | IPO
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					0				0
Adjustments | Commissions | Private placement
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					0				0
Adjustments | Other
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance					(1,020)		$ 241		(326)
Exercise of stock options					0				0
Share‑based compensation					0				0
Net loss					74				(620)
Ending balance					(946)				(946)
Adjustments | Other | IPO
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					0				0
Adjustments | Other | Private placement
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock					$ 0				$ 0
Adjustments | Common Stock | Commissions
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)					0				0
Beginning balance					$ 0				$ 0
Ending balance (in shares)					0				0
Ending balance					$ 0				$ 0
Adjustments | Common Stock | Other
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)					0				0
Beginning balance					$ 0				$ 0
Ending balance (in shares)					0				0
Ending balance					$ 0				$ 0
Adjustments | Additional Paid‑In Capital | Commissions
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance					0				0
Ending balance					0				0
Adjustments | Additional Paid‑In Capital | Other
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance					0				0
Ending balance					0				0
Adjustments | Accumulated Deficit | Commissions
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance					(3,753)				(2,830)
Net loss					(369)				(1,292)
Ending balance					(4,122)				(4,122)
Adjustments | Accumulated Deficit | Other
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance					(1,020)				(326)
Net loss					74				(620)
Ending balance					$ (946)				$ (946)

[1] Certain prior period amounts have been revised to correct immaterial errors. See Note 1 for more information.

[2] Certain prior period amounts have been revised to correct immaterial errors. See Note 1 for more information.