audit logs in AWS RDS Oracle database

I have a requirement to capture config changes in the logs. I tried it and it is not writing to AWS RDS audit logs. example

CREATE USER test IDENTIFIED BY "test123!" default tablespace users temporary tablespace TEMP_DBPRODB profile DEFAULT;

GRANT CONNECT, RESOURCE to test;

alter user test profile SERVICE_ACCOUNT;

it is not getting captured

I tried it on a non AWS RDS Oracle database and the above changes are gettting written to the audit log

here is what I see in the audit log

Tue Jun 13 11:47:53 2023 -04:00 LENGTH : '254' ACTION :[101] 'CREATE USER test IDENTIFIED BY * default tablespace users temporary tablespace TEMP profile DEFAULT' DATABASE USER:[1] '/' PRIVILEGE :[6] 'SYSDBA'

Tue Jun 13 11:48:13 2023 -04:00 LENGTH : '183' ACTION :[31] 'GRANT CONNECT, RESOURCE to test' DATABASE USER:[1] '/' PRIVILEGE :[6] 'SYSDBA'

Tue Jun 13 11:50:15 2023 -04:00 LENGTH : '191' ACTION :[39] 'alter user test profile SERVICE_ACCOUNT' DATABASE USER:[1] '/' PRIVILEGE :[6] 'SYSDBA' CLIENT USER:[6] 'oracle'

The parameter setting for this database I see is SQL> show parameter audit_trail NAME TYPE VALUE

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audit_trail string DB, EXTENDED

Whereas for AWS RDS database that value is null.

Is that the reason the audit logs is not capturing those changes?