If your application is API-only and does not render a frontend, you can still inspect DebugKit toolbar data directly.
Open the toolbar endpoint with the request's DebugKit ID:
http://localhost/debug-kit/toolbar/<debugkit-id>
The <debugkit-id> value is returned in the response headers:
X-DEBUGKIT-ID: 5ef39604-ad5d-4ca4-85d8-8595e52373bb
For example:
http://localhost/debug-kit/toolbar/5ef39604-ad5d-4ca4-85d8-8595e52373bb