Using iTween to rotate toward a target's blue axis

Unity Engine
1

How can I use iTween to make an object look at the blue axis of another object?

I tried this code:
iTween.lookTo(gameObject,{“transform”:obstacle.transform.forward , “time”:2});

But I get an error:
Cannot cast from source type to destination type.

The idea is that in design mode if I change the orientation of the target object (making its blue axis point to a new direction) I want the host to point to that direction too.

2

Have you tried something like this:

iTween.rotateTo(gameObject,{"rotation":obstacle.transform.eulerAngles});

Let me know if this gets you closer to a solution.