How to get four window viewport?

Hi, I am trying turn viewport from single prespective to four window(top, right, side, prespective) mode. As per documentation theres square toggle button somewhere top right that I cant find for some reason. Heres what my viewport looks like- no toggle button. Can anyone help out. Thanks in advance

Yeah there should be a square button to the right of the camera speed. What version of the engine are you using?

I can’t see for some reason. The version is 4.13.0, should be quite latest, only downloaded few days back.