Could not update Bubble 3.0.0 on Xamarin.Android

[Ma Ding]

I was using version 1.0.0 on Xamarin.Android.
When I try to update to Bubble 3.0.0, it shows error.

Could not install package 'Bubble 3.0.0'. You are trying to install this package into a project that targets 'MonoAndroid,Version=v7.1', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author.