Download using HACS or manually put it in custom_components folder.
The integration supports discovery of devices, so any fans should be automatically discovered. If not you may try to add it manually through the integration configuration.
If there are problems, please enable debugging in configuration.yaml
# Logging
logger:
default: warning
logs:
custom_components.pax_ble: debug
@PatrickE94 for the Calima driver: https://github.com/PatrickE94/pycalima
@MarkoMarjamaa for a good starting point for the HA-implementation https://github.com/MarkoMarjamaa/homeassistant-paxcalima