A sample app showing how to integrate the Capacitor Firebase Authentication Plugin from CapAwesome Team in an Ionic VueJS Application
you will need to add to root of project a .env file to project
VUE_APP_FIREBASE_API_KEY=
VUE_APP_FIREBASE_AUTH_DOMAIN=
VUE_APP_FIREBASE_PROJECT_ID=
VUE_APP_FIREBASE_APP_ID=
you will need to follow directions for adding google auth to project
I needed google and phone number auth for a mobile solution, mostly google and I wanted a plugin that could handle all of the oauth stuff form me with simple configuration and finally firebase was the database solution.
So basically I use the Plugin to get the auth credential and then I login using the javascript sdk. Once the user is logged in, I do not need the listener from the plugin to let me know if a user is logged in or not; i juts use the js sdk auth listener to fing my user and thats it.