OK. OKHttpUtils2 is fine for sending messages, but I am not really looking to send messages from the App.
What I am after is being able to receive the messages, like I currently do with Firebase like Firebase messaging
I can see all the parts (code for the manifest, java code, API_KEYS etc.) But I don't know how to implement this within B4A having never developer on Android with anything other that B4A since day one....
Does anyone have the necessary code to implement this please ? Happy to donate
You need to follow their instructions. This needs a bit more work, implementing the manifest-changes, adding Service(s), using the SDK. Probably you need to write a wrapper of it. You can use JavaObject too if you are familar with it.