Trouble importing popup auth providers

[mattbodman]

When I try to use a popup auth provider, like this:

import { Auth } from @angular/fire/auth;
import firebase from 'firebase/compat/app';
import GoogleAuthProvider = firebase.auth.GoogleAuthProvider;

export class AuthService {

    constructor(private auth: Auth) {}

signInWithPopup(this.auth, new GoogleAuthProvider());

etc...

I get errors like "cannot read properties of undefined" (reading GoogleAuthProvider). I have also tried importing with import firebase from 'firebase/compat' but a different version of the same thing happens.

Any clues would be great. I should mention:

@angular/core 13.2.4
@angular/fire 7.2.1
firebase 9.6.7