yes it's possible
Let's start from here :
https://www.youtube.com/watch?v=ES26E4r_uEU
https://www.youtube.com/watch?v=4daTy4zjqiQ
Creating a Chat Application in App Inventor 2
App inventor. Chat FirebaseDB. Chat con CloudDB.
Firebase Chat and Label HTML Content
🔥 Register and Login using Firebase Authentication for your app
Firebase with Web Component