Try to first call BAPI_INTERNALORDER_GETDETAIL, then use its result to call the change BAPI.
PS: A BAPI implementing FM is always RFC enabled els it is not a BAPI.
Try to first call BAPI_INTERNALORDER_GETDETAIL, then use its result to call the change BAPI.
PS: A BAPI implementing FM is always RFC enabled els it is not a BAPI.