curl --request POST \
  --url https://api.staging.kathan.tech/campaign/{campaign_id}/start \
  --header 'Authorization: Bearer <token>' \
  --header 'X-User-ID: <api-key>'

{
  "id": "<string>",
  "name": "<string>",
  "assistant_id": "<string>",
  "channel": "<string>",
  "phone_number_id": "<string>",
  "status": "<string>",
  "max_concurrency": 123,
  "retry_policy": {},
  "speech_settings": {
    "style": "neutral",
    "responsiveness": "balanced",
    "interruptions": "on",
    "emotions": "natural"
  },
  "assistant_name": "<string>",
  "caller_id_number": "<string>",
  "schedule_start_time": "<string>",
  "schedule_end_time": "<string>",
  "campaign_context": "<string>",
  "opening_message_template": "<string>",
  "use_returning_greeting": false,
  "use_short_term_summaries": false,
  "short_term_summaries_limit": 123,
  "machine_detection_timeout_seconds": 123,
  "recipient_list_id": "<string>",
  "recipient_list_name": "<string>",
  "recipient_list_row_count": 123,
  "counts": {},
  "created_at": "<string>",
  "updated_at": "<string>"
}