Trying to trigger an outbound call via the CXone Personal Connection API from a backend service. Sending a POST to /api/v2/outbound/contacts with a valid contactId and campaignId. The request body looks like {"contactId": "123", "campaignId": "456"} but getting a 400 response. The error message says Invalid campaign configuration. Checked the docs and it seems straightforward. Am I missing a required header or field in the JSON payload?