first, if it is a unionpay single-currency card and the merchant supports the unionpay channel, it will be directly converted into RMB by swiping US dollars, and there will be a certain exchange fee. Repay directly in RMB.

second, if it's a dual-currency credit card, swipe the VISA or MasterCard channel. If you swipe the US dollar, it will be recorded in US dollars. If you don't have it, you can deposit it in RMB to purchase foreign exchange for repayment.

thirdly, if it is a full-currency credit card, there is no exchange fee for swiping US dollars. Repayment can be made directly in RMB shown in the bill.