Line renderer from UI to 3D GameObject

Hi,

I would like to draw a line between a UI element to a 3D game object.

I tried something like this, and some other variations

 void Update ()
     {
         Vector2 pos;
         RectTransformUtility.ScreenPointToLocalPointInRectangle(CanvasRect, target.position, null, out pos);
         startPos = CanvasRect.transform.TransformPoint(pos);
 
         LineRenderer lr = gameObject.GetComponent<LineRenderer>();
         lr.SetPosition(0, startPos);
         lr.SetPosition(1, endPos);
     }

But of course it gives weird results, like it appears correct in the editor but not in the game itself.

What's the best way to draw a line between a UI element (screen space overlay) to a game object (world space)?

Thanks