Mix reality with 3d Content

Hello, I’m working on a project with Unreal Engine 5.2 in which I animate an astronaut via motion capture. I used MediaPipe4U for this. Now I want to put a person’s face in the helmet. A green screen, two cameras and two capture cards are available. Is there a way to use facial recognition to center the face so that it is always in the middle?
In addition, it should be scaled so that it fits. What is the way to do this?
Sorry for my bad english, i´m German and using Google translater.