Where is the any button?

Unless you have a specially adapted version of the standard keyboard, no such key exists.

This is related to an apocryphal story about a novice computer user, who encounters the instruction "hit ANY key to continue". Seeing other keys such as enter, escape, shift, and control, the user calls technical support to find out which key on the keyboard is the ANY key. While this seems unbelievably naive, similar queries have been made about various computer instructions since the earliest days of personal computers.