If you don't have a receipt, you should pay the bill. If your unit is more formal, you should go to a regular supermarket or a place where you can buy food for your relevant unit. If the business scale is large, you should go back and get a big receipt. When you use it, you should have a picking list and take the food money to the cashier for reimbursement. If you really can't get the invoice, it is best to establish and improve this link according to experience. Because the market price of many vegetables always fluctuates, this gives some people with speculative psychology an opportunity, so it is best to find a place to buy according to the relevant income during the safety period, and don't be greedy for temporary cheap.