Hi,
I’m trying to add the Google-plus login to my app, but no matter what I do I cannot get it working on a real Android device.
So far I was able to get the idToken from this plugin 
cordova-plugin-googleplus
Using Firebase’s singInWithCredential(idToken) I get an error that said:
This app, identified by the domain where it is hosted, is not authorized to use Firebase Authentication with the provided API key. Review your key configuration in the Google API console.
I want to point out that I follow all the steps for the installation, SHA1 key are correct and I am using signed APKs.
Using the facebook plugin, retrieving the token and signInWithCredential worked without any issue.
Thanks in advance!