There is no real need to sign in for TV provider with streaming providers, as these providers have apps with all their channels self-contained.
Philo on the App Store - Apple
Hulu on the App Store - Apple
Signing in with a TV provider is meant as a simplified way to register with separate apps all at once (single sign-on). It is meant for cable subscribers and package deals. For some reason Hulu supports this too. Philo is not on this list of participating providers.
TV providers that let you sign in on your iPhone, iPad, or Apple TV - Apple Support