This is usually done on the server side. The frontend application sends a request to the server to receive a list of products. The server returns a list of products that a given user should see. And the frontend application displays a list of products based on the response from the server.

Of course, you can do all this on the client side using hard-coded data. But generally such things are done in connection with a server and a database that stores data about the product, information about which user should have access to a given product, etc.

An admin panel is usually created to manage products (adding, deleting, other settings such as product visibility for a given user). Admin panel is connected to the server and downloads and updates product information in the database.