I regularly use Python Markdown when working with Jupyter notebooks. It is actually straightforward to set up in Jupyter, but I always forget the exact steps to be followed whenever I set up Jupyter notebook especially after installing a new OS.
So, there are those steps, I note here to help myself in future. First install notebook extensions package. Documented at https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/install.html
pip install jupyter_contrib_nbextensions
Then install the extension helping to configure extensions with UI.
pip install jupyter_nbextensions_configurator
Then enable extensions package:
jupyter nbextensions_configurator enable --user
Now we will get “Nbextensions” tab on notebook home page where we can enable/disable each of the extensions.