File::copyDirectory return nothing

I'm able to copy files using Storage::copy but when i tried to copy folder with File::copyDirectory, it doesn't change anything. Why is that?

My Code:

 public function pasteDocument(Request $request)
    {      
      if(Session::get('clipboard') == "copy"){
      // copy to disk
          File::copyDirectory('public\img', 'public\js', true);
         }
      return redirect()->back();
    }

via Dikna R Yahdi