Live Link Face App with VR

Good day all, sorry to be a bother, but hopefully someone will be able to help me.

I wanted to use my live link face app to track my face onto my character, and it works great, but I only want it to track the mouth area. I have no morphs on the eyes/nose/cheeks etc, as I don’t plan to use them. My problem, is that when I put on my VR headset, the AR camera on my ios no longer sees my face as a face. I was hoping that the live link face app could be edited so that it only searches for a mouth so that I can still move my character’s mouth, while in VR.

If anyone knows how to do this, or a different app that can look specifically for mouth and does not require eyes, nose, or forehead visibility, I would really appreciate it. If it helps I am specifically using Oculus Rift.