Floating Action Button problem on xamarin forms.

I am using xamarin forms 3.4 and for floating action button the plugin is SuaveControls.FloatingActionButton. When i use this plugin on list there are a shown a white background behind the floating button also when i install this plugin a warning sign showing on the plugin.
Can anyone tell me what is the problem why warning sign showing. i think for that plugin does not working properly.

Thanks in advance.