Because the user's electronic device does not support it, the APP has not been updated to the latest version, the card has been lost, and the card has been changed. Discount is not available. Coupon can reduce the price of products, and it is a common commercial promotion tool for consumers. Coupons can be printed on the inserts of magazines, attached to newspapers, pasted on the packaging of products, put in shops for people to get, and sometimes even sent to the street for distribution.