Open the terminal and type the following command:

npm install passport passport-local --save

Place the following code after the app express variable:

// Passport configuration
require('./server/config/passport')(passport);

Now, we need to create a passport.js file and the necessary code inside the config folder. We can name this file with any name. However, to demonstrate the use of the passport module, we use the same name from the module. Create a passport.js file in the config folder and place the following code:

// Import passport module
var LocalStrategy = require('passport-local').Strategy;

// Import the user model
var User = require('../../server/models/user');

module.exports = function...