How to interact with a button in Unity 3d?

Question

C++ / C#

Tell me how to interact with the button. In my case, the button that restarts the game, I wrote void press in the code, do I need to make a link to the button and why does it not spawn the object?
Object spawn code (attached to void press):
inst_obj = Instantite (obj, new Vector3 (0, 0, 0), Quaternion.identeti) as GameObject;
Maybe something is wrong with him? (no errors in console)