Delegate approval person in NAV

In NAV, we can setup a document created by user A and that document must be approved by user B before that document released to certain department.
For example, user A create a Purchase Request (PR) and then the PR will be approved by user B before the PR released to Purchasing Department.

Sometimes, user B might be on leave for a certain periode, so who will approve the PR ?

In NAV, we can substitute user B with user C, so everytime user A create a PR and send for approval, the approval request email will be sent to user C automatically.

To setup for a substitute person, open the menu Approval setup and then assign user C as a substitute person for approval

How about, if the NAV administrator / NAV super user forget to assign for substitute person and the PR already sent for approval to user B ?

No worries, NAV has a Delegate button to do it.

Login as user B, or as NAV Super user and then open the Approval Entries menu and then choose the PR which want to delegate to user C