Where is the "Extensions" menu?

I just installed SU 2016. It doesn’t have an extensions menu. How do I install extensions?
How do I find them (before and after installed)?
How do I get the SketcUcation extension manager?

Hi i have the same problem:

i can’t find this menu:

If you haven’t installed any plugins, the menu is hidden but will be visible after the installation of the first plugin with an item in that menu.


What do you see instead?

ok thanks, i have just to install and it will be, thanks i understand