With the Port execution agent enabled (with a GitLab/Webhook backend), the headers you configure in the SSA UI are not automatically sent as HTTP headers.

By default they stay inside the JSON payload, so you do need a custom “control the payload” mapping in the agent to forward them as headers.

In any other case, you can define the payload directly via Port.

The request is to have the default behavior to send all the headers configured in the UI automatically.