When I put my password Environment Variables it won't work - next.js

Question

My code works as below in my localhost. What I'm trying to do is put my password in my .envlocal but it won't work.
working code
export default function (req, res) {
let nodemailer = require('nodemailer')
const transporter = nodemailer.createTransport({
port: 465,
host: "smtp.gmail.com",
auth: {
user: 'myEmail#gmail.com',
pass: 'password123',
},
secure: true,
});
const mailData = {
from: 'keshibatmail#gmail.com',
to: 'kensukeshibata#gmail.com',
subject: `Message From ${req.body.name}`,
text: req.body.message + " | Sent from: " + req.body.email,
html: `<div>${req.body.message}</div><p>Sent from: ${req.body.email}</p>`
}
transporter.sendMail(mailData, function (err, info) {
if(err)
console.log(err)
else
console.log(info);
})
console.log(req.body)
res.send('success')
}
What I tried.
My next.js is
"next": "10.x"
,
So I should be able to use this since my next.js is higher than 9.4 https://nextjs.org/docs/api-reference/next.config.js/environment-variables
I made .env.local file
NEXT_PUBLIC_PASSWORD=password123
then process.env.NEXT_PUBLIC_PASSWORD
I tried without NEXT_PUBLIC_ as well.
I get this error.
response: '535-5.7.8 Username and Password not accepted.
const transporter = nodemailer.createTransport({
port: 465,
host: "smtp.gmail.com",
auth: {
user: myEmail#gmail.com,
pass: process.env.NEXT_PUBLIC_PASSWORD,
},
secure: true,
});