According to national requirements, different product categories need different certificates. For example, if it is self-produced food, it needs workers' health certificates, and packaged food needs food safety and related, trademark registration and authorization, and agency authorization.
Basically, large supermarkets rarely cooperate with individuals. You usually need a company or brand company to authorize you to do it. If you are generally qualified, you will be asked to provide the corresponding supporting documents when signing the contract. Every supermarket will be different, so we can't generalize from point to area.