Created file structure and initialized express.js backend

app/backend/index.js

@@ -0,0 +1,14 @@
+// backend/index.js
+const express = require('express');
+ 
+const PORT = process.env.PORT || 3010;
+const app = express();
+ 
+app.use((req, res, next) => {
+  res.setHeader('Access-Control-Allow-Origin', '*');
+  next();
+});
+ 
+app.listen(PORT, () => {
+  console.log(`Server listening on ${PORT}`);
+});