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

{
  "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_events": 123,
  "leaderboard": [
    {
      "user_id": 123,
      "referrals_count": 123,
      "total_amount_kopeks": 123,
      "total_amount_rubles": 123,
      "telegram_id": 123,
      "username": "<string>",
      "full_name": "<string>"
    }
  ]
}