receive mail with nodemailer without setting "Allow less secure apps to access" - node.js

Question

I want to ask something about nodemailer, i make code like
Var client = nodemailer.createTransport ({
Service: 'gmail',
Auth: {
User: 'example#gmail.com', // Your email address
Pass: '123' // Your password},
Tls: {rejectUnauthorized: false}
});
And this works, but after successful delivery, when I have to receive email messages that have been sent, I need to enable gmail settings like "Allow less secure apps to access". I do not want to set it.
So how do I send emails from example#gmail.com TO example1#gmail.com, without setting "Allow less secure apps to access" and message directly accept in email box !!??? Or any other plugin that should be added ??
THANX;)

Answer 1

Obtain accessToken & refreshToken from Google OAuth2.0 Playground,
clientId & clientSecret from Google developer console
const nodemailer = require('nodemailer');
const xoauth2 = require('xoauth2');
var express = require('express');
var router = express.Router();
var smtpTransport = nodemailer.createTransport('SMTP',{
service:"Gmail",
auth:{
XOAuth2: {
user:'sender#emailaddress.com',
clientId: 'your-client-id',
clientSecret: 'your-cliet-secret',
accessToken:'your-access-token',
refreshToken: 'your-refresh-token'
}
}
});
router.get('/emaildemo', function(req, res, next) {
var mailOptions = {
from: 'sender#emailaddress.com',
to: 'xxx#email.com',
subject: 'TEST SUBJECTT',
text: 'TEST MAIL',
};
smtpTransport.sendMail(mailOptions, function(error, info){
if(error){
console.log('Error Occured', error);
return res.send(error);
}
return res.send("mail send successfully");
});
});
module.exports = router;

Answer 2

You need to get the access token, you cannot give it statically.
googleapis can be user for gmail.
for example:
const { google } = require('googleapis');
const { OAuth2 } = google.auth;
const {
MAILING_SERVICE_CLIENT_ID,
MAILING_SERVICE_CLIENT_SECRET,
MAILING_SERVICE_REFRESH_TOKEN,
SENDER_EMAIL_ADDRESS,
OAUTH_PLAYGROUND //https://developers.google.com/oauthplayground
} = process.env;
const oauth2Client = new OAuth2(
MAILING_SERVICE_CLIENT_ID,
MAILING_SERVICE_CLIENT_SECRET,
OAUTH_PLAYGROUND
);
oauth2Client.setCredentials({
refresh_token: MAILING_SERVICE_REFRESH_TOKEN,
});
//>>> get the accessToken
const accessToken = oauth2Client.getAccessToken();
let transporter = nodemailer.createTransport({
service: 'gmail',
auth: {
type: 'OAuth2',
user: SENDER_EMAIL_ADDRESS,
clientId: MAILING_SERVICE_CLIENT_ID,
clientSecret: MAILING_SERVICE_CLIENT_SECRET,
refreshToken: MAILING_SERVICE_REFRESH_TOKEN,
accessToken,
},
});
let mailOptions = {
from: 'no-reply#blah.com',
to: 'to_blah#blah.com',
subject: 'test',
text: 'test'
};
let result = await transporter.sendMail(mailOptions);