A method of operating a user equipment, UE, in a wireless communication system is provided. The method includes obtaining a discovery key for discovery of a UE-to-Network relay from a first application function. The method includes using the discovery key for discovery of the UE-to-Network relay over a PC5 interface. A method of operating a user equipment-to-network, UE-to-NW, relay node in a wireless communication system is also provided. The method includes obtaining a discovery key for discovery of a user equipment, UE, from a first application function. The method includes using the discovery key for discovery of the UE over a PC5 interface.