The steps are as follows:

1. Select the group buying coupon you want to buy on Dianping and complete the payment process.

2. On the Dianping App, enter the "My" page and find order management.

3. In the order details, confirm that the order status of the purchased group purchase coupon is "paid".

4. When purchasing in the store, find the QR code of the group purchase coupon in the order details, and show the QR code to the merchant for verification. The merchant will scan the QR code to confirm.

5. The merchant will confirm the cancellation after you provide the QR code of the group purchase coupon.