curl --request GET \
  --url http://localhost:7701/api/v1/subscriptions/coupons \
  --header 'X-API-Key: <api-key>'

{
  "data": [
    {
      "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "code": "SUMMER20",
      "name": "20% off Summer Sale",
      "description": "<string>",
      "discount_type": "percentage",
      "discount_value": 20,
      "max_redemptions": 100,
      "redemptions_count": 5,
      "max_cycles": 3,
      "valid_from": "2023-11-07T05:31:56Z",
      "valid_until": "2023-11-07T05:31:56Z",
      "is_active": true,
      "created_at": "2023-11-07T05:31:56Z"
    }
  ]
}