Rotate the Marker to the outside according to the camera

Hello everyone, I try to add a hotspot tag to the scene, which seems to work normally. What I need to solve is that when the camera rotates to view the model, the label line can be automatically adjusted according to the camera’s angle of view. Whether it is necessary to reverse to the outside instead of keeping the same direction all the time. Thank you.

The best effect is like this picture. How to weigh the angle of camera and 3D coordinate point.

This is a small example I did, please help me, thank you!