curl --request GET \
  --url https://api.useduro.com/v1/promo-codes/{id} \
  --header 'Authorization: Bearer <token>'

{
  "id": "<string>",
  "code": "<string>",
  "discountType": "<string>",
  "discountValue": 123,
  "duration": "<string>",
  "redeemedCount": 123,
  "remaining": 123,
  "active": true,
  "expiresAt": "<string>",
  "createdAt": "<string>"
}