access-control-allow-origin nodejs express

1. Install Express using the following command:

npm install express

1. Create a new file named app.js and add the following code:

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

app.use((req, res, next) => {
  res.header('Access-Control-Allow-Origin', '*');
  next();
});

app.get('/', (req, res) => {
  res.send('Hello World!');
});

app.listen(3000, () => {
  console.log('Server running on port 3000');
});

1. Run the Node.js application using the command:

node app.js