curl --request GET \
  --url https://api.example.com/api/campaigns/{campaign_id}/calls

{
  "items": [
    {
      "id": 123,
      "to_number": "<string>",
      "status": "<string>",
      "name": "<string>",
      "task_id": 123,
      "call_id": "<string>",
      "call_status": "<string>",
      "call_duration": 123,
      "call_recording_url": "<string>",
      "from_number": "<string>",
      "initiation_time": "2023-11-07T05:31:56Z",
      "answer_time": "2023-11-07T05:31:56Z",
      "end_time": "2023-11-07T05:31:56Z",
      "hangup_cause_name": "<string>",
      "call_transcription": [],
      "call_insights": {},
      "created_at": "2023-11-07T05:31:56Z"
    }
  ],
  "total": 123,
  "page": 123,
  "page_size": 123,
  "total_pages": 123
}