Oracle Message RMAN-06217 - not connected to auxiliary database with a net service name

ERRORnot connected to auxiliary database with a net service name
CAUSEA command that moves files from the target instance to the auxiliary instance was requested. Such a command requires a net service name be present in the connect string used to connect to the auxiliary instance.
ACTIONIssue a CONNECT AUXILIARY command and include a net serice name in the connect string. That service name must be valid on the target instance.