firebase cloud functions send email

1const functions = require('firebase-functions');
2const admin = require('firebase-admin');
3const nodemailer = require('nodemailer');
4const cors = require('cors')({origin: true});
5admin.initializeApp();
6
7/**
8* Here we're using Gmail to send 
9*/
10let transporter = nodemailer.createTransport({
11    service: 'gmail',
12    auth: {
13        user: 'yourgmailaccount@gmail.com',
14        pass: 'yourgmailaccpassword'
15    }
16});
17
18exports.sendMail = functions.https.onRequest((req, res) => {
19    cors(req, res, () => {
20      
21        // getting dest email by query string
22        const dest = req.query.dest;
23
24        const mailOptions = {
25            from: 'Your Account Name <yourgmailaccount@gmail.com>', // Something like: Jane Doe <janedoe@gmail.com>
26            to: dest,
27            subject: 'I\'M A PICKLE!!!', // email subject
28            html: `<p style="font-size: 16px;">Pickle Riiiiiiiiiiiiiiiick!!</p>
29                <br />
30                <img src="https://images.prod.meredith.com/product/fc8754735c8a9b4aebb786278e7265a5/1538025388228/l/rick-and-morty-pickle-rick-sticker" />
31            ` // email content in HTML
32        };
33  
34        // returning result
35        return transporter.sendMail(mailOptions, (erro, info) => {
36            if(erro){
37                return res.send(erro.toString());
38            }
39            return res.send('Sended');
40        });
41    });    
42});