Adding placeholder like an image in middle of screen but on detected plane surface

Hello there,
I’m Swift developer and almost new to Unity, I got On demand trainings but couldn’t find out how can I add a place holder in middle of screen on top of recognized plane surface and change the position according to user way of looking, I know Apple doesn’t let us to have access to eye tracking, I can add object in pinch interaction position but I want to add that placeholder and get its position for adding object there. is there any hits for that I know how to do it in mobile apps but not for Vision Pro.
Thank you.