Instagram authentication with Firebase, Ionic 2

I’m trying to authenticate Instagram with a Firebase integration, following the JS example here.

I have set up Firebase in app.component.ts using

import * as firebase from 'firebase';

which has seemingly worked.

On home.html I simply have a login button:

<button ion-button (click)="connect()">Login</button>

Which calls this on home.ts.

connect(){
    console.log("Connecting")
    window.open('http://localhost:8080/redirect', 'firebaseAuth', 'height=315,width=400');
}

Now is where I’m a little confused. The log in is successful, and the pop-up Instagram closes as should happen with the node server shown in Firebase’s example.

I then have, in the constructor, for change detection:

  this.zone.run(() => {
    this.checkAuth()
  });

With this.checkAuth():

firebase.auth().onAuthStateChanged(function(user) {
        if (user) {
          // User is signed in.
          console.log('Connect:', user);
        } else {
          // No user is signed in.
          console.log('No connect:');
        }
      });

Nothing appears in console after window close. However I’m pretty sure I’m missing something.
Any help greatly appreciated.
Thank you!