The specific steps are as follows: 1. Open the WeChat app on the mobile phone, click Add in the upper right corner and scan it; 2. Scan the QR code of the catering invoice provided by the code merchant; 3. Return to my card package, find the invoice, and the electronic catering invoice is issued. Alipay: 1. Open Alipay app on your mobile phone and click Add in the upper right corner; 2. Click Scan to scan the QR code of the catering invoice provided by the code merchant; 3. Return and click the card package; 4. Click on the ticket; 5, click on the invoice, find the invoice, catering electronic invoice issued. China Unionpay Quick Pass: 1. Open China Unionpay Quick Pass app on your mobile phone and click on more services; 2. Click Invoice; 3. Click the scan code to invoice, and the electronic catering invoice provided by the scan code merchant will be issued.