Question Firebase authentication for WebGL with Linux server?

Greetings,

I'm developing a multiplayer game with a WebGL client (and possibly adding desktop/mobile clients in the future). The server will run on a Linux instance in AWS.

I would like to use Firebase for authentication as well as for database storage and I planned to make all the API calls from the Linux server (a Unity server build deployed to a Linux instance).

My question is what kind of App do I register in Firebase? For Unity it only gives me iOS and Android as options but if I select Web it wants me to download and add some Script code to the "body" of my app.

Since the server is basically a desktop build that doesn't work for me either.

Has anybody else done this (is it even possible)?

Thanks in advance.