A fan can be controlled in many ways.
First the speed can be controller continuous, airflow or in upto 4 steps (levels)
When your Fan supports continuous (0-100%) it needs a 5.001 DataPointType listen and set address:
Same for Airflow, you need a DPT 9.009 set and listen address. And you specify the minimum and maximum:
When you choose level, you can specify 1 to 4 levels. They can all be controlled by 1 byte (DPT 5.010):
Or by a bit (DPT 1.001) individually :
Another option is the mode:
When you choose anything other than "Not supported", you need to specify another two group addresses (DPT 1.001) for set and listen of the mode:
This way you can set the automatic mode from HomeKit, for instance.