Cannot sign into apple tv app on a fire stick 4k

When I try to sign into apple TV app on the fire stick 4k, it doesn't give any code and when signing via the remote, I just get "verification failed".

Any idea what could be causing this issue?

These are the things I already tried:

* Check for app updates and no new updates available

* Reset app data, cache data etc., followed by restart Fire stick

* Uninstall apple TV app, restart fire stick and re-install the app

* Factory reset and re-install app

* Check for firmware updates and no new updates available

I already have the two factor auth enabled. Please help.