expand loopback backend (restaurant-reservation system)

Hello! I need someone who has experiences with the loopback backend framework. I am developing a restaurant-reservation-system, where customers have the opportunity to order a dishmenu and reserve a table. (Note: The system is designed for several restaurants, so each restaurant can offer their dishmenus). When the user clicks on a dishmenu of his/her choice, he/she can also make a table reservation. The restaurant-owner can look up all requests in a table and confirm the request or reject it. I need someone who knows how to expand the backend.