The Trace is showing that Apigee Edge is receiving your inbound request, and is handling it. The API proxy you are using appears to be a “pass through” - in other words it doesn’t do anything to modify the request.
From the screenshot, it appears that the 404 is being returned by the backend system. I don’t know what that system is, or how you configured it, but Apigee Edge is telling you that the backend system is affirmatively telling you “I don’t have a resource like that”.
If you explore in the trace UI, you should be able to see:
- the exact request being sent to the backend
- the response being returned by the backend
Either of these may provide some additional hints as to what is going wrong for you.