Let GUI.TextBlock change with mesh coordinates，How to do it？

Questions
1

Babylon.js - GUI demo (babylonjs.com)

Just like sphere1~7 here

2

I am not familiar with many of them recently, so I have many problems. Thank you very much for your help. My English level is not good. Please forgive me for my poor expression

3
4

linkWithMesh(mesh),How to get the UI link with the mesh?

5

This is exactly what the doc above is describing. Not sure to understand the question ?