503 Service Unavailable after deploy NextJS app - node.js

Question

so, after trying a few times, it is clear that I am doing something wrong but I do not realize what. My steps are:
rm -rf .next/ && npm run build
upload .next, package.json,next.config.js and server.js to cPanel file manager
create node JS app from cPanel with 14.18.3 version. (on my local node -v show me 14.18.1, but on cPanel I don't have this version)
run npm install with success
then i'm geting 503 service unavailable.
server.js
// server.js
const { createServer } = require('http');
const { parse } = require('url');
const next = require('next');
const dev = process.env.NODE_ENV !== 'production';
const hostname = 'localhost';
const port = process.env.PORT || 3000;
// when using middleware `hostname` and `port` must be provided below
const app = next({ dev, hostname, port });
const handle = app.getRequestHandler();
app.prepare().then(() => {
createServer(async (req, res) => {
try {
// Be sure to pass `true` as the second argument to `url.parse`.
// This tells it to parse the query portion of the URL.
const parsedUrl = parse(req.url, true);
const { pathname, query } = parsedUrl;
if (pathname === '/a') {
await app.render(req, res, '/a', query);
} else if (pathname === '/b') {
await app.render(req, res, '/b', query);
} else {
await handle(req, res, parsedUrl);
}
} catch (err) {
console.error('Error occurred handling', req.url, err);
res.statusCode = 500;
res.end('internal server error');
}
}).listen(port, (err) => {
if (err) throw err;
console.log(`> Ready on http://${hostname}:${port}`);
});
});
package.json scripts
"scripts": {
"dev": "node server.js",
"build": "next build",
"start": "NODE_ENV=production node server.js"
},
next.config.json
/** #type {import('next').NextConfig} */
const nextConfig = {
basePath: '/apps/nextjs-cpanel',
trailingSlash: true,
reactStrictMode: true,
sassOptions: {
additionalData: `#import "./styles/variables.scss"; #import "./styles/mixins.scss";`,
}
};
module.exports = nextConfig;
on cPanel application root is apps/nextjs-cpanel, application url is my-domain/apps/nextjs-cpanel and application startup file server.js