Prompt, please, as the data is being transferred to Google Play services?

Prompt, please, as the data is being transferred to Google Play services? And if it is possible an example of how this happens. The information that is given on this site https://github.com/playgameservices/play-games-plugin-for-unity/blob/master/RTMP.md I read. But still do not understand exactly how peredovat data. Help me please.