const html = '<h1>Hello, World!</h1>';

const express = require('express');

const app = express();
app.get('*', (req, res) => {
// That's all you need to do! If you pass a string to `res.send()`,
// Express sets the response-type header to `text/html`
res.send(html);
});

const server = await app.listen(3000);

// Example of using the server
const axios = require('axios');

const res = await axios.get('http://localhost:3000');
res.headers['content-type']; // 'text/html; charset=utf-8'
res.data; // '<h1>Hello, World!</h1>'