Do I have to tie a bank card to my Changsha one-code city?

No, my Changsha One Code Pass is a software that displays the QR code of taking the subway and bus. You need to show the QR code when you take the bus. You need to pay for the bus. The bank card must pay the corresponding fare. You can also use payment software such as WeChat and Alipay to pay. I don't need to bind a bank card for Changsha One Code Pass. My official version of Changsha app is a convenience service software jointly created by Changsha Data Resources Administration and Changsha 168 municipal departments and units under the guidance of Changsha Municipal People's Government.