Fetching Purchase Order to Zoho Creator

Fetching Purchase Order to Zoho Creator

Hi yalls. Pretty confused with the API documentation for Creator and Inventory integration. I am trying to retrieve a specific Purchase Order from my inventory account to Creator, but all I can do it retrieve all Purchase Orders (see img below)

What should I do to retrieve a specific Purchase Order as I need to retrieve the line items and the "get all Purchase Orders" method I am using (as per the docs) does not consist of the line items.