transform.LookAt(target) not working when instantiate

Unity Engine
1

hi … just to know
why if i use
transform.LookAt(target); (apply script to the prefab)
and then instantiate this prefab, why transform.LookAt(target);
not working ?

how can i fix this please ?
thanks alot for any help.

here is my code… .js

var my_target: Transform;
function Update() {
transform.LookAt(my_target);
}
2

thanks … i got this

target = GameObject.FindGameObjectWithTag("Player").transform;

and now is working…
but put this post to help more people…