How to find coordinates and place image on top of ARSCNView (ARFaceTrackingConfiguration)?

I'm working on the application where we use ARFaceTracking technology. I need to do something similar to this video from mortal kombat: https://youtu.be/JBGpEXbPhms?t=6. I use ARSCNView, I need to add new node with image to appear on the screen which will be shown from a random side of the screen. Which node should I use? How can I calculate coordinates for different angles?