You need an addZ-Stick for the SmartHome Box (available in the HOMEPILOT store at https://de.homepilot-smarthome.com/produkte/licht-heizung/zubehoer-und-ersatzteile/addz-stick-f.-gateway-premium) which must be plugged into the SmartHome Box.
To register, the light source must be in the Delivery status state. The light must be switched on and the registration mode on the SmartHome Box must be started.