Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Cash and cash equivalents (Details)

v3.21.1
Cash and cash equivalents (Details) - USD ($)
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Cash and cash equivalents        
Cash $ 58,450,680 $ 2,060,624    
Cash equivalent 70,999,996 6,500,000    
Cash and cash equivalents $ 129,450,676 $ 8,560,624 $ 13,951,951 $ 6,839,172