Share based compensation - Summary of stock option activity (Details) - USD ($)	3 Months Ended			9 Months Ended	12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Number of shares
Outstanding at the beginning	2,919,493		2,414,303	2,414,303
Granted			210,800
Forfeited			(198,400)
Outstanding at the end		2,919,493			2,414,303
Weighted average exercise price
Outstanding at the beginning (in dollars per share)	$ 5.25		$ 2.17	$ 2.17
Granted (in dollars per share)			11.69
Forfeited (in dollars per share)			$ (2.22)
Outstanding at the end (in dollars per share)		$ 5.25			$ 2.17
Weighted average remaining remaining term (in years)
Outstanding		9 years			8 years 2 months 12 days
Granted (in years)			9 years 9 months 18 days
Aggregate intrinsic value
Outstanding at the beginning (in dollars)	$ 20,558,299		$ 53,659,966	$ 53,659,966
Granted (in dollars)			3,825,276
Forfeited			$ (6,587,328)
Outstanding at the end (in dollars)		$ 20,558,299			$ 53,659,966
2016 Omnibus Inventive Plan [Member]
Number of shares
Outstanding at the beginning		2,426,703
Granted	82,890	587,030
Exercised	(511,065)	(4,960)
Forfeited	(102,507)	(89,280)
Outstanding at the end	2,388,811		2,426,703	2,388,811
Weighted average exercise price
Outstanding at the beginning (in dollars per share)		$ 14.58
Granted (in dollars per share)	$ 13.68	14.94
Exercised (in dollars per share)	(2.22)	(3.07)
Forfeited (in dollars per share)	(3.07)	$ (7.86)
Outstanding at the end (in dollars per share)	$ 6.04		$ 14.58	$ 6.04
Weighted average remaining remaining term (in years)
Outstanding	8 years 1 month 6 days		8 years 8 months 12 days
Granted (in years)	9 years 10 months 24 days	9 years 10 months 24 days
Forfeited (in years)	0 years
Exercised (in years)	0 years
Aggregate intrinsic value
Outstanding at the beginning (in dollars)		$ 30,388,510
Exercised (in dollars)	$ (3,602,645)	(42,385)
Forfeited	(635,543)	$ (339,082)
Outstanding at the end (in dollars)	$ 12,447,723		$ 30,388,510	$ 12,447,723
2021 Omnibus Incentive Plan
Number of shares
Options vested and exercisable	1,250,340			1,250,340
Weighted average exercise price
Options vested and exercisable	$ 1.86			$ 1.86
Weighted average remaining remaining term (in years)
Options vested and exercisable	6 years 2 months 12 days
Aggregate intrinsic value
Options vested and exercisable	$ 9,418,169			$ 9,418,169
As previously reported
Number of shares
Outstanding at the beginning (as previously reported)					486,755
Weighted average exercise price
Outstanding at the beginning (as previously reported)					$ 10.79
Weighted average remaining remaining term (in years)
Outstanding at the beginning (as previously reported) (in years)					8 years 9 months 18 days
Aggregate intrinsic value
Outstanding at the beginning (as previously reported) (in dollars)					$ 19,571,655
Adjustment
Number of shares
Retroactive application of reverse recapitalization					1,927,548
Weighted average exercise price
Retroactive application of reverse recapitalization					$ (8.62)