Getting push-plugin to work for android

Hi folks,
I have iOS push notifications working very well using https://github.com/phonegap/phonegap-plugin-push
For Android, it compiles but when I run the app, push registration fails. I went to google developer console and generated a sender-ID.

their website talks about GCM support libraries et al - and just puts a link to the GCM site.

Can someone please explain succinctly what one needs to do to integrate this into ionic build android in a way that pulls in whatever libraries are needed?

For example they say:

As of version 1.3.0 the plugin has been switched to using Gradle/Maven for building. You will need to ensure that you have installed the Android Support Library version 23 or greater, Android Support Repository version 20 or greater, Google Play Services version 27 or greater and Google Repository version 22 or greater.

I have all those packages - but how do I tie them into my app?

thanks!