SUMMARY OF PRINCIPAL ACCOUNTING POLICIES - Held-to-maturity (Details) - USD ($)
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
SUMMARY OF PRINCIPAL ACCOUNTING POLICIES      
Held-to-maturity investments $ 10,046,645 $ 0  
Investment gain from treasury note $ 174,380 $ 0 $ 0