1. First of all, on pos, we know that there is a function called printing, which can print the last or any sum we spend. You can print as long as you enter the voucher number, but you can't print after the pos machine has settled.

2. Next, we click the OK button and look for print in the page. If you can't find it, it's a management problem. After we click Print, we can choose (print the last stroke).

Next, we can make up other receipts. We need to enter voucher numbers, but we can't print them without them.

4. Finally, if it is not necessary to enter the voucher number of the sum, the voucher number is unknown, and log in to the POS merchant management on the computer.

The POS machine reads the magnetic stripe information on the cardholder's bank card through the card reader, the POS machine operator inputs the transaction amount, and the cardholder inputs the personal identification information (i.e. password). The POS machine sends the information to the issuing bank system through the UnionPay center to complete the online transaction, give the information of success or failure, and print the corresponding bill.