After over 6 years firebase test lab CAN be used with Ionic apps (also react native for that matter, and, I guess, any other framework). BUT with limitations: User can't record scripts, so the robotest is rather brittle, as it'll simply "click around" and report if any click resulted in a crash.

To run the "click around" robotest you'd need to add Oauth with Google to your app (if there's auth-wall in your app and you'd want to pass that). If robotest detects such button it'll click it and log with test account.

Automatic sign-in: If your app has a sign-in screen that uses a Google account for authentication, Robo test uses a Google test account, unless you provide test account credentials for custom sign-in.

https://firebase.google.com/docs/test-lab/android/robo-ux-test#sign-in