OnTop is not a ressource, but rather a topic. There are 3 different ontop placements. So we have 3 different resources to add an ontop placement to a real estate. The requests and methods of the 3 ressources are similar, only the type of the OnTop placement changes.
NOTICE: if an object is deactivated in the is24 publish channel 10000, every given OnTop Placement will also be deactivated!