RealityKit - Add a line from one Model entity to center of screen as it moves

Question

Hello I would like to achieve the following functionality: I have a modelentity in my ARView and I want to be able to draw a line that grows and shrinks as the user moves their camera away or towards the modelentity.

Here are my questions:

1. How do I even start to create a simple 2D line on the screen from one stationary point to another? Do I have to use a box with a small width?

2. How can I get this line to grows and shrinks as the camera moves around?

Thank-you.