Extensions using Python

Is it possible to write simple extensions/plugins for Avogadro in Python?
I see nothing about this topic in the manual (https://avogadro.cc/docs/), though previous forum posts suggest there should be.

Also, I am using Avogadro mostly in Windows. It is not clear why the Python terminal doesn’t show up. I have found previous remarks here that there should be two types of Windows executive, with and without Python, but the executables are automatically downloaded from Avogadro / sourceforge.net, and no option or link is offered to any other version. Any hint or suggestion is appriciated.