How to unmask historical (External) bank accounts?

Summary:

We disabled the masking(updated as show all) and "Mask External Bank Account Data program" ran automatically. Still it did not unmask historical bank accounts for suppliers. Trying to run unmask process manually, but couldn't find the process in schedule process.

Content (please ensure you mask any confidential information):

As per note R12:AP: How to Change the Supplier Bank Account Masking Payables? (Doc ID 877074.1) We need to run this process manually. While we are tying to run the process from Schedule Process, this program isn't available.

FYI - user has IT Security Manager, Financial Application Administrator and Application Implementation Consultant