createRoot(...): Target container is not a DOM element

Question

This error keeps occuring . I use codesandbox to create the React applications. Currently I was hulding a Food Order app using React. And somehow this error keeps popping up . I have imported react and react-dom everywhere. The error keeps saying about some rendering gone wrong. Attached are some images and a snippet of code I am sharing , which is showing error in the index.js file.

import ReactDOM from 'react-dom/client';
import './index.css';
import App from './App';

const root = ReactDOM.createRoot(document.getElementsByClassName('root'));
root.render(<App />);