You'll need to copy down all of the example code so that the menu.py can find the plugins folder.
Easiest way to do this:
git clone https://github.com/pimoroni/dot3k
Then cd into dot3k/python/examples/dothat/advanced
and run it.
Usually this is done for you when you run the curl get.pimoroni.com/dot3k | bash
installer and you should find the examples in ~/Pimoroni/dot3k
( aka /home/pi/Pimoroni/dot3k
)