Significant accounting policies - Summary of reconciliation of numerator and denominator of diluted net loss per share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Significant accounting policies
Net (loss) income	$ (9,495,996)	$ (2,966,203)	$ (12,569,390)	$ (4,840,463)
Cumulative dividends on Series A preferred stock		(36,286)		(72,173)
Net loss attributable to common stockholders	$ (9,495,996)	$ (3,002,489)	$ (12,569,390)	$ (4,912,636)
Basic weighted average number of shares outstanding	63,731,582	36,659,685	63,684,906	35,872,780
Diluted weighted average number of shares outstanding	63,731,582	36,659,685	63,684,906	35,872,780
Basic net loss per share attributable to common stockholders	$ (0.15)	$ (0.08)	$ (0.20)	$ (0.14)
Diluted net loss per share attributable to common stockholders	$ (0.15)	$ (0.08)	$ (0.20)	$ (0.14)