Unable to send emails to Gmail account

server.js

//Lets require/import the HTTP module
var http = require('http');

//Lets define a port we want to listen to
const PORT=1030; 

//We need a function which handles requests and send response
function handleRequest(request, response){
    response.end('Welcome to Node.js localhost!\nPath Hit: ' + request.url);
}

//Create a server
var server = http.createServer(handleRequest);

//Lets start our server
server.listen(PORT, function(){
    //Callback triggered when server is successfully listening. Hurray!
    console.log("Server listening on: http://localhost:%s", PORT);
});

var nodemailer = require('nodemailer');

// create reusable transporter object using SMTP transport
var transporter = nodemailer.createTransport();

// NB! No need to recreate the transporter object. You can use
// the same transporter object for all e-mails

// setup e-mail data with unicode symbols
var mailOptions = {
    from: 'Rahul Desai <[email protected]>', // sender address
    to: '[email protected]', // list of receivers
    subject: 'Hello ✔', // Subject line
    text: 'Hello world ✔'
    // , // plaintext body
    // html: '<b>Hello world ✔</b>' // html body
};

// send mail with defined transport object
transporter.sendMail(mailOptions, function(error, info){
    if(error){
        return console.error(error);
    }
    console.log('Message sent: ' + info.response);
});