The following assumes you are using python from the MongoDB toolchain.
/opt/mongodbtoolchain/v4/bin/python3
(mongo-python3) deactivate # only if you have another python env activated
sh> /opt/mongodbtoolchain/v4/bin/python3 -m venv cm # create new env
sh> source cm/bin/activate # activate new env
(cm) python -m pip install -r requirements.txt # install required packages
(cm) python start.py # run the calibrator
(cm) deactivate # back to bash
sh>
(cm) python -m pip install <package_name> # install <package_name>
(cm) python -m pip freeze > requirements.txt # do not forget to update requirements.txt