API_BILLING_DOCUMENT_SRV returns no header pricing data

We are seeing nary header pricing information coming backmost from this work and wonderment if it is simply a bug that SAP should analyse oregon fix.

Even successful the tryout feature, nary billing documents instrumentality header pricing.

https://api.sap.com/api/API_BILLING_DOCUMENT_SRV/tryout

Has anyone been capable to retrieve header pricing conditions for billing documents with this service?