Show me clear way to get code completion with PyGObject

I installed PyGObject fine. The code will run, but there is no code completion capability.

Did alt+enter with cursor caret inside Gtk in line below, but nothing happened.

from gi.repository import Gtk

Went to 'Help' menu >Edit Custom Properties; added idea.max.intellisense.filesize=25000

Redid alt+enter with cursor caret inside Gtk and popup had:

Convert to 'import gi.repository' >

Add alias to 'Gtk' >

......but got no 'Generate stubs for binary module'.

Is there some clear step by step procedure to get Pycharm to do code completion for PyGObject??