Oracle Message ORA-16052 - DB_UNIQUE_NAME attribute is required

ERRORDB_UNIQUE_NAME attribute is required
CAUSEThe DB_UNIQUE_NAME attribute is required when DG_CONFIG is enabled.
ACTIONUse the DB_UNIQUE_NAME attribute to specify a valid Data Guard Name for the destination. The list of valid DB_UNIQUE_NAMEs can be seen with the V$DATAGUARD_CONFIG view.