While ARPlane detection, How to show message "Move Closer" if user is very far from object.

I am detecting ARPlanes with ARSessionWrapperDelegate. While scanning Object in App, if the user is far from object, I want session message on screen that tell user to "Move Closer" like in IOS Measure App.

While ARPlane detection, How to show message "Move Closer" if user is very far from object.
 
 
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