Pywikibot is actively deprecating Python2 support (T213287: Drop support of Python 2.7). The documentation at https://wikitech.wikimedia.org/wiki/Help:Toolforge/Pywikibot is still python2 focused.
Someone needs to help the pywikibot Toolforge community understand how to run their bots under python3 and direct them to T242120: Python 2 to 3 support request for additional support at needed.