How to use dbms_metadata to generate DDL for a Unified Auditing Policy

SQL> set long 5000
SQL> select DBMS_METADATA.GET_DDL('AUDIT_POLICY','ORA_LOGON_FAILURES')  from dual;

DBMS_METADATA.GET_DDL('AUDIT_POLICY','ORA_LOGON_FAILURES')
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   CREATE AUDIT POLICY "ORA_LOGON_FAILURES" ACTIONS  LOGON