Download the PDF for a purchase order. The document is rendered when you call this, from the order's current state and the tenant's PDFs & Emails settings, so it is the same document the product's Download button produces rather than a stored copy of one sent earlier. The file name derives from the tenant's purchase-order title template with "Purchase Order" abbreviated to "PO" and spaces removed, so the default template yields `PO104.pdf` for an ordered purchase order and `RFQ104.pdf` for one still in Draft. The title printed inside the document keeps its spacing; only the file name is squashed.