curl --request GET \
  --url http://localhost:8080/promo-offers/{offer_id}

{
  "id": 123,
  "user_id": 123,
  "notification_type": "<string>",
  "discount_percent": 123,
  "bonus_amount_kopeks": 123,
  "expires_at": "2023-11-07T05:31:56Z",
  "is_active": true,
  "effect_type": "<string>",
  "created_at": "2023-11-07T05:31:56Z",
  "updated_at": "2023-11-07T05:31:56Z",
  "subscription_id": 123,
  "claimed_at": "2023-11-07T05:31:56Z",
  "extra_data": {},
  "user": {
    "id": 123,
    "telegram_id": 123,
    "username": "<string>",
    "first_name": "<string>",
    "last_name": "<string>",
    "full_name": "<string>"
  },
  "subscription": {
    "id": 123,
    "status": "<string>",
    "is_trial": true,
    "start_date": "2023-11-07T05:31:56Z",
    "end_date": "2023-11-07T05:31:56Z",
    "autopay_enabled": true
  }
}