Intended document style is not appearing in Approval notification

Summary:

How to bind the "display name" configured in "Manage Document Styles" to be visible on PO approval notification?

We have separate document style for each department. Document styles with display name like Standard Purchase Order - IT, Blanket Purchase Agreement - IT, Standard Purchase Order - Network, Blanket Purchase Agreement - Network, etc. When creating the PO/ BPA we select the document style based on the respective department.

In PO UI, we can see the display name (Standard Purchase Order - IT, Blanket Purchase Agreement - IT, Standard Purchase Order - Network, Blanket Purchase Agreement - Network).

E.g. Standard Purchase Order - IT is not appearing in the purchasing approval title, instead the standard style 'Purchase Order' is appearing. We need the display name as in PO to be fetched to the approval notification.