Convertible debt - Schedule of KSP Convertible Notes Valuation Assumptions (Details) - KSP Convertible Notes	Mar. 31, 2024	Dec. 31, 2023	Sep. 29, 2021
Risk free interest rate
Debt Conversion [Line Items]
Embedded derivative liability, measurement input	0.047	0.042	0.011
Expected life of options
Debt Conversion [Line Items]
Embedded derivative liability, measurement input	2.5	3.8	5
Expected dividend yield
Debt Conversion [Line Items]
Embedded derivative liability, measurement input	0.000	0.000	0.000
Expected stock price volatility
Debt Conversion [Line Items]
Embedded derivative liability, measurement input	0.71	0.63	0.66
Share Price
Debt Conversion [Line Items]
Embedded derivative liability, measurement input	1.03	4.76	12.56