Hello @BERNARD Thomas ,
Azure IoT Central is a SaaS platform for IoT. It is based on Azure IoT PaaS resources like IoT Hub, Aure Stream Analytics, and Device Provisioning Service.
The reference documentation you found is for the full Device Provisioning.
The DPS supports adding an alternative Device ID and Device Twin Tags.
These are provided to the IoT Hub chosen by the DPS so the IoT Hub can create the device registration and eg. start automatic device configuration.
Because you use Azure IoT Central, you are limited by what is offered in the current interface, either the portal or the REST API.
At this moment, both interfaces are not offering support for adding DPS tags. You can only provide the registration ID and optional device ID (I assume this is the 'displayName').