Journal post by approver

Summary

Journal approval follows the employee supervisor hierarchy and once the journal is reviewed and approved the approver should have the ability to post the journal.

Content

Hi,

One of the requirements for General Ledger posting is the preparer should not be able to post. Using sandbox customization we hid the 'POST' button on Create Journal UI to restrict user to post, but how can we prevent preparer to post the spreadsheet journals?

And , Journal approval follow the employee supervisor hierarchy and once the journal is reviewed and approved the approver should have the ability to post the journal. Using supervisory hierarchy GL approval rules, we are able to send the journal for approval. However unable to post automatically upon the approval?  How can we achieve this?