1. Open Alipay's subway QR code. 2. Click Manage at the top right of the screen to open the management interface and select Traffic Card Management. 3. Enter my traffic card and display all traffic card information under the current account. 4. Click on the bus code of Beijing Rail Transit to display my traffic card interface. 5. Click on the card details to enter the detailed information display interface. 6. Click Invoice to enter the invoice page, and select the itinerary to be invoiced. 7. Click Invoice and select the type of invoice. Here, select electronic invoice. 8. Enter the billing information and email address, and download the electronic invoice in the email address after issuing the invoice.