CXone Personal Connection API 403 when injecting traceparent header

Trying to trigger an outbound call via the CXone Personal Connection API (POST /api/v2/communication/outbound/calls). The goal is to inject a traceparent header for OTel span propagation, but the basic call is failing.

Endpoint: POST /api/v2/communication/outbound/calls

Here’s the payload:

{
 "recipient": { "phoneNumber": "+639171234567" },
 "campaignId": "abc-123",
 "traceparent": "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01"
}

Getting a 403 Forbidden. The error message says “Invalid header format”. I’ve verified the token works for other endpoints like /api/v2/users/me.

Is the Personal Connection API blocking custom headers? Or am I missing something in the OAuth scope? The docs don’t mention header restrictions.

Checked the Jaeger UI. No spans are appearing. Suspect the header isn’t being propagated to the underlying Genesys Cloud API.

Anyone else hit this? Need a workaround for tracing outbound calls.