Update index.js

client/src/index.js

@@ -1,8 +1,16 @@
 import React from 'react';
 import ReactDOM from 'react-dom';
+import './index.css';
 import App from './App';
+import reportWebVitals from './reportWebVitals';
 
-ReactDOM.render(<App />, document.getElementById('root'));
-
-
+ReactDOM.render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>,
+  document.getElementById('root')
+);
 
+// If you want to start measuring performance in your app, pass a function
+// to log results (for example: reportWebVitals(console.log))
+reportWebVitals();