curl --request GET \
  --url http://localhost:8080/contests/referral

{
  "items": [
    {
      "id": 123,
      "title": "<string>",
      "contest_type": "<string>",
      "start_at": "2023-11-07T05:31:56Z",
      "end_at": "2023-11-07T05:31:56Z",
      "daily_summary_time": "<string>",
      "timezone": "<string>",
      "is_active": true,
      "final_summary_sent": true,
      "created_at": "2023-11-07T05:31:56Z",
      "updated_at": "2023-11-07T05:31:56Z",
      "description": "<string>",
      "prize_text": "<string>",
      "daily_summary_times": "<string>",
      "last_daily_summary_date": "2023-12-25",
      "last_daily_summary_at": "2023-11-07T05:31:56Z",
      "created_by": 123
    }
  ],
  "total": 123,
  "limit": 123,
  "offset": 123
}