After the user completes the order and confirms the receipt, he can click on the corresponding entrance on the homepage of Pinduoduo or the personal center page, or consult on the official customer service page, or directly enter the full refund view. Full cash back means that after the user confirms the receipt of goods, the system will automatically distribute the cash back amount to the user's account in the form of coupons. These coupons can be used in subsequent shopping, which is equivalent to directly deducting the shopping amount and helping users save money.