v3.21.1
Stock warrants - Additional Information (Details) - Common stock - $ / shares
Nov. 06, 2020
Jan. 31, 2021
Jan. 31, 2020
Class of Warrant or Right [Line Items]      
Number of warrants (in shares)   0 75,137
Exercise price (in USD per share)     $ 8.02
Common stock issued upon the exercise of warrants (in shares) 60,338