expdp without password

I was wondering if you can export, (expdp), without a password, (or wallet etc.) similar to using other utilities such as 'Sqlplus / as sysdba', or 'rman target /'?

I have a password script and can create a centralized password file (unencrypted), but since I have been able to do most everything else without a password, I would rather not implement it just because of this issue.

I've googled (with mixed results -- seen an answer that did not work). Did not find it (an example) in the manual.

Best Regards,

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