Improbable tab in unity

Hi everyone,
I do not see the Improbable tab in unity 5.6.0.
How can I visualize it?

Improbable?

Edit:
You might have to add the improbable package:
https://docs.improbable.io/reference/12.0/tutorials/unity-player-movement
Some packages add menu items as helpers for installation and configuration.

exactly, I mean the tab highlighted in red in the figure104477-tab.jpg