Gui's Arrow Issue

Hello there! I have an issue with compass system, I made a a billboard and arrow inside player’s head as you see here:
image

so i have no idea about how to make it look at a target, i tried so many times but i failed, so im asking for help guys.

As a helper, what should I do?:
type your code inside a function called “Cast”

Could I see how the arrow looks from a players point of view?

image