How do I invoke pymcuprog?
Protip: never run 'pip3 install' without --user; when not working in a special prefix! othewise, it installs stuff in system-wide locations, which are different for different systems and sometimes (and that's the case here) not even looked in by default.
So, uninstall what you've installed using pip3 again, then set up a Python virtual env:
python3 -m venv cloudsenvironment
Then activate it:
source cloudsenvironment/bin/activate
Then you can run pip3 without danger of polluting/breaking your system. That activation bent a few paths, so that with the shell you ran that command from, commands and Python modules are now run from the folder that was created during venv creation. Try it out!