create a router by itself and call it in another file - express - backend

Central_Router.js

// inside /api/apiRoutes.js <- this can be place anywhere and called anything
const express = require('express');

// if the other routers are not nested inside /api then the paths would change
const userRoutes = require('./users/userRoutes');
const productRoutes = require('./products/productRoutes');
const clientRoutes = require('./clients/clientRoutes');

const router = express.Router(); // notice the Uppercase R

// this file will only be used when the route begins with "/api"
// so we can remove that from the URLs, so "/api/users" becomes simply "/users"
router.use('/users', userRoutes);
router.use('/products', productRoutes);
router.use('/clients', clientRoutes);

// .. and any other endpoint related to the users resource

// after the route has been fully configured, then we export it so it can be required where needed
module.exports = router; // it is recommended that this be the last line on the file

index.js

const express = require('express');

const apiRoutes = require('./api/apiRoutes');

const server = express();

server.use('/api', userRoutes);

server.listen(8000, () => console.log('API running on port 8000'));