Income taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income taxes

Schedule of components of income taxes

	Year ended December 31,
	2021		2020		2019
Foreign	$	(13,229,828)	$	(27,215,385)	$	(25,268,373)
Domestic		(23,897,475)		(26,263,427)		(2,791,434)
Net loss	$	(37,127,303)	$	(53,478,812)	$	(28,059,807)

Summary of reconciliation of the effect of applying federal statutory rate to the net loss and the effective income tax rate

	Year ended December 31,
	2021		2020		2019
Statutory federal income tax rate	21.0	%	21.0	%	21.0	%
Earnings in jurisdictions taxed at rates different from the statutory U.S. federal tax rate	(0.1)	%	0.2	%	0.4	%
Permanent differences	—	%	1.7	%	3.7	%
Changes in valuation allowance	(18.2)	%	(22.5)	%	(25.1)	%
Other	(2.7)	%	(0.4)	%	—	%
Effective income tax rate	—	%	—	%	—	%

Summary of significant components of deferred taxes

	December 31,
	2021		2020
Deferred tax assets:
Net operating loss carryforward	$	38,773,870	$	32,183,004
Stock compensation		3,341,338		1,358,554
Lease liability		47,677		70,192
Gross deferred tax assets		42,162,885		33,611,750
Valuation allowance		(42,115,543)		(33,541,533)
Total deferred tax assets		47,342		70,217
Deferred tax liabilities:
Fixed assets		(818)		(1,130)
Right of use asset		(46,524)		(69,087)
Total deferred tax liabilities		(47,342)		(70,217)
Net deferred tax assets (liabilities)	$	—	$	—