As per the material UI documentation, https://next.material-ui.com/components/buttons/
you can
import LoadingButton from '@material-ui/lab/LoadingButton';
However, I don't see this folder anywhere in mui/lab and the import throws an error.
I ran yarn add @material-ui/lab already.
I also have "@material-ui/core" already.
Do I need to install something for 'next mui' as I see the documentation url is also different: https://next.material-ui.com/
While most of components I have been using are here: https://material-ui.com/