This document:
https://learn.pimoroni.com/article/fitting-picade-plasma-buttons#picade-plasma-software
Refers to using this link:
https://get.pimoroni.com/plasma
Which doesn't seem to do everything anymore, as the library this script really wants is here:
https://github.com/pimoroni/plasma-python
However, I don't know how to raise this as a bug!
(I thought I should leave a breadcrumb here incase others get into the same loop)