@inlovewithpda Away from my PC so I can't test, but I've seen this on PostmarketOS. Add 2 options to the install command:
pip3 install pygenda --user --no-deps
--break-system-packages
--no-deps tells pip3 to not install any depencies. The --break-system-packages sounds scary (probably on purpose) and permits pip3 to install in environments with other package managers. It's safe here as "--no-deps" means only Pygenda is installed, & there's no Debian Pygenda package to conflict with.
@semiprime works. No I have to find the shortcut to make a screenshot :)