Can't install NuGet packages in Xamarin Forms

I am trying to install a NuGet package in Xamarin Forms and in all the ones I try to install I get the same error.

"Package X is not compatible with netstandard2.0"

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The package I want to install is this: https://www.nuget.org/packages/Refractored.FloatingActionButton/.

Any idea how to fix this error?