it just works

frontend/src/index.tsx

@@ -0,0 +1,10 @@
+import React from 'react'
+import ReactDOM from 'react-dom/client'
+import { App } from './App'
+
+const root = ReactDOM.createRoot(document.getElementById('root')!)
+root.render(
+    <React.StrictMode>
+        <App></App>
+    </React.StrictMode>
+)