Loome Publish now has a Postman Workspace containing collections that illustrate various API scenarios. You can access this Workspace and work through the sample scenarios to build your own solutions.
If it does not contain the scenario you wish to use, please contact us at firstname.lastname@example.org.
You can find the Loome Publish Workspace here - Loome Publish Workspace.
Authentication is via your own account using OAuth, the Workspace documentation provides a detailed explanation of how to use Azure CLI to authenticate and provide a bearer token.
You will need to update the Workspace with your Loome Publish URL and your OAuth token.