material-ui Drawer - findDOMNode is deprecated in StrictMode

Question

I have a simple ReactJS app based on hooks (no classes) using StrictMode.

I am using React version 16.13.1 and Material-UI version 4.9.10.

In the Appbar I a

Answer 1

This is a StrictMode Warning

Strict mode checks are run in development mode only; they do not impact the production build.

ReactDOM.render(
  
    
  ,
  document.getElementById('root')
);

to

ReactDOM.render(
    ,
  document.getElementById('root')
);