curl --request GET \
  --url https://api.steppay.kr/api/v1/subscriptions/{subscriptionId}/items/{itemId}/options \
  --header 'Secret-Token: <api-key>'

{
  "id": 123,
  "name": "<string>",
  "options": [
    {
      "id": 123,
      "name": "<string>",
      "price": 123,
      "quantity": 123,
      "parent": 123
    }
  ],
  "depth": 123
}