1) First of all, to launch to the Hiring Settings page, please navigating to the sidebar menu and search for "Settings" --> Click sub-menu "Hiring".  

2) Then, navigating to the "Approver" tab.

3) Click on the "Edit Approver" then click on the "Select" button. 

4) Select the approver, and click "Done".

5) Remember to click "Save" to update it.

6) The approver was updated successfully and shown on the table.

When HR preparing and sent the offer letter to the candidate, the approver set in hiring settings would appear as an official designatory name on the candidate offer letter.