FaceTime Video Call without FaceTime App?

I reside in the U.S. and I have a cellular service with AT&T. I'm able to make FaceTime Video calls even though I do not have the FaceTime app on my iPhone 14 pro max. How is it possible to make a FaceTime call (it does say “FaceTime Video” under the call in the call log) without having the actual FaceTime app on my phone?