How do I add custom page in nodejs app directory

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Javascript

Node.js

I am trying to add a sitemap page in nodejs, but it's not working.

What I have tried:

I tried this but the page runs on a specific port only:
example.com:3001/sitemap.xml. However, I want to run it on example.com. I am confused, but running it on default HTTP 80 because nodejs web app process is already running on that port and it may create conflict.

const express = require('express');
const app = express();

// Serve the sitemap.xml file
app.get('/sitemap.xml', (req, res) => {
  res.sendFile('sitemap.xml', { root: __dirname });
});

// Other routes and middleware for your website...

// Start the server
app.listen(3000, () => {
  console.log('Server is running on port 3000');
});