curl 'https://api.goatpay.com.br/v1/coupons/get/clx_coupon' \
  -H 'X-API-Key: gp_live_SUA_CHAVE'

{
  "success": true,
  "message": "Cupom encontrado",
  "data": {
    "id": "clx_coupon",
    "code": "VERAO10",
    "discountType": "PERCENT",
    "discountValue": 10,
    "uses": 5,
    "maxUses": 100,
    "status": "ACTIVE"
  },
  "requestId": "req_abc"
}