Install

pipx install "git+https://github.com/Blackman99/certfan@v0.1.0"
# or
pip install https://github.com/Blackman99/certfan/releases/download/v0.1.0/certfan-0.1.0-py3-none-any.whl

Check it: certfan --version and certfan demo (runs offline against three local TLS servers). Also runnable as python -m certfan.