If it is a US dollar card, it will be charged in US dollars according to the exchange rate announced by VISA. You need to bind the US dollar account for repayment or deposit it in the RMB entrusted bank to purchase foreign exchange at the exchange rate on the repayment date. This method requires Visa to pay a 2% conversion fee.
If you have a single UnionPay card, the POS consumption supporting UnionPay will be directly converted into RMB according to the exchange rate of the day, and RMB repayment can be deducted from your binding account.