Authorization failed while exporting to Object storage from ATP

Summary:

Hi I am getting authorize failed error while exporting data from ATP to bucket using dbsm_cloud.export_data package.

ORA-20401: Authorization failed for URI - https://objectstorage.{region}.oraclecloud.com/n/{namespace}/b/{bucket}/o/{objectname}/xx.csv

 ORA-06512: at "C##CLOUD$SERVICE.DBMS_CLOUD", line 1651

 ORA-06512: at "C##CLOUD$SERVICE.DBMS_CLOUD", line 8493

 ORA-06512: at "C##CLOUD$SERVICE.DBMS_CLOUD", line 8512

I am not using pre-authenticate URL due to security reasons.

need a bit more info on

dbms_credential.create_credential(
    credential_name => 'tim_hall_credential',
    username        => 'tim_hall',
    password        => 'password');

if someone can share a sample working code would be great.