You can use `npm run build` to build the frontend and backend. Use `NEXT_PUBLIC_BACK_HOST=localhost:4000 npm run dev` to run the frontend and `PORT=4000 node dist/index.js` to run the backend.
You could also run `NEXT_PUBLIC_BACK_HOST='https://server.exozy.me' npm run dev` if you are only developing the frontend and connecting to the public backend server.