Go to "Manager" / “Settings” and choose the applicable company and cost object, if you are an approver for multiple entities and / or cost objects.
Choose the user you want to appoint as delegate and an optional expiring date. Click on "Save".
The delegated approver will be able to see the delegated expense reports under “My tasks” in the “Approvals” tab or on the "Manager" / “Approval” page.
In the History section, on the bottom of each expense report, the delegate approver will be logged as “Approved by ABC on behalf of DEF”.