Why the message don't appear on the page when MediaLibrary is used?

I'm using Laravel nova also the ClassicO\NovaMediaLibrary\MediaLibrary.

And with Laravel Nova I can use the help method like this:

Select::make('Option')
                ->options(
                    Post::active()
                )->help(
                    'Please select a option'
                )

However using the same help() method and also the MediaLibrary like this:

  MediaLibrary::make('Image')
                ->help('Only png.')
                ->types(['Image']),

The help message don't appear on the page. Do you know what can be the issue?