The type or namespace barcode is not found

[ComptonAlvaro]

I have tried to run this the examplo of Vision, that I have found here: https://github.com/xamarin/GooglePlayServicesComponents/tree/master/samples/com.google.android.gms/play-services-vision

However, when I try to compile, I get many errors, for example that the namespace or type Barcode is not found, or the type CameraSource, and I can't using using Android.Gms.Vision, because Gsm is not found.

I am using the version 16.8.5 (visual studio 2019 community).

What could I run this example?

Thanks.