Trouble Downloading Purchase Requisitions using REST and Visual Builder Add-In for Excel

Trying to use the VB add-in for Excel to access Purchase Requisitions. Read-only, to start with (though ultimately, I hope to use the approach to create unpublished requisitions). But I'm stuck at the starting gate.

Requests by Requisition Number or for all Requisitions return no results, but also don't error.

• Network monitor shows the response includes a link to a "purchaseRequisitions" collection, but with count: 0 results.
• API base is /fscmRestApi/resources/11.13.18.05/purchaseRequisitions
• I've both started from scratch and worked through the documentation provided in the How to create and manage Requisitions using REST and Oracle Visual Builder Add-In for Excel