how to get ssl on express server code example

Example: express ssl

// create certificate g-ssl.config.js

var { writeFileSync } = require('fs');
var { resolve } = require('path')
var selfsigned = require('selfsigned');
var chalk = require('chalk');

var gssl = selfsigned.generate([{ name: 'commonName', value: 'localhost' }], {
	keySize: 2048,
	algorithm: 'sha256',
	days: 90,
	clientCertificateCN: 'localhost'
});

writeFileSync(resolve(process.cwd(), 'ssl/key.pem'), `${gssl.private}`, 'utf8');
writeFileSync(resolve(process.cwd(), 'ssl/cert.pem'), `${gssl.cert}`, 'utf8');

console.log(chalk.green.bold('Generate Certificate SSL Succeffuly'));

// app.js

require('dotenv').config();
const https = require("https");
const http = require('http');
const express = require('express');
const { resolve } = require('path')
const { readFileSync } = require("fs");
const logger = require('morgan');
const chalk = require('chalk');
const app = express();

app.use(logger('dev'));
app.set('views', 'views');
app.set('view engine', 'ejs');
app.set('x-powered-by', false);

app.get('/', (req, res) => {
	 res.render('index', {
	 	 desc: req.protocol === 'https'
	 	 ? `Express using SSL certificate for using ${req.protocol} protocol`
	 	 : `Express using SSL certificate for using ${req.protocol} protocol`
	 })
});

http.createServer(app).listen(process.env.PORT, () => console.log(chalk.white.bold('http server on port 3000')));

if(process.env.NODE_ENV === 'development') {
	const options = {
	  key: readFileSync(`${resolve(process.cwd(), 'ssl/key.pem')}`),
	  cert: readFileSync(`${resolve(process.cwd(), 'ssl/cert.pem')}`),
	};
	https.createServer(options, app).listen(3001, () => console.log(chalk.white.bold('https server on port 3001')));
}

console.log(chalk.white.bold(`NOTE: important this SSL for Development Mode not for Production Mode`));
console.log(chalk.white.bold(`NOTE: because this ssl certificate's signature was created manually`));
console.log(chalk.white.bold(`NOTE: SSL certificate is used to use authentication using Oauth or package like Passport for auth third part \n`));