The USB interface of the cash register can be connected to the QR code scanning platform to realize the QR code payment function. The specific steps may vary depending on the cash register model and scanning platform, but generally speaking, you can follow the following steps:

Confirm that the cash register has a USB interface and that the interface can be used to connect external devices.

Prepare a scanning device that is compatible with the cash register, such as a barcode scanner such as XTIOT XT2001C. Make sure the scanning device supports USB connection and is compatible with the cash register.

Use a USB cable to connect the QR code scanning device to the USB interface of the cash register. Make sure the connection is tight to avoid loosening or falling off.

Turn on the QR code scanning function or related applications of the cash register. You can usually find the QR code scanning function entrance on the cash register software interface.

In the QR code scanning function interface, select the USB-connected QR code scanning device as the input device. This can usually be selected in software settings or device configuration.

Wait for the cash register to recognize and connect the scanning device. Once the connection is successful, you can start using the QR code scanning device to scan and pay.