POST method to On-Prem Microsoft Dynamics via OData/SOAP in n8n through HTTPS request node?

Hi everyone,

I’m trying to post data to an on-premise Microsoft Dynamics NAV/BC web service using the HTTP Request node in n8n. The service is hosted locally (not cloud) and exposed via a SOAP or OData endpoint.

I can successfully use GET, but I’m struggling with the POST request to create records (e.g., Purchase Orders). Has anyone managed to set up a working POST to an on-prem Dynamics endpoint?
What authentication and headers should I use?

Appreciate any guidance or examples!

(self hosted n8n)