Hi team, hoping for some help in creating a new ION API suite to use ION gateway to call a 3rd party API.
The 3rd party API is secured via client credentials - I am able to get the token using Postman; so I know my client credentials work. I want to embed the token request into my ION API call.
Here is my ION API configuration.

When executing the API via the gateway in Postman I get a 403. I have already configured Postman as a backend service; and can use it to call other 3rd party APIs via the gateway - but this does not seem to pass the client credentials through to the service. My OAuth2 requests to the ION auth server are working - I an getting the 403 from what I assume is the inttra.com endpoint specified above.

Is the above config correct? Is there anything else I can try to get this working?