curl --request GET \
  --url https://{operatorDomain}/v1/admin/finance/vouchers/{id} \
  --header 'Authorization: Bearer <token>'

{
  "data": {
    "id": "vch_01HZX...",
    "code": "WELCOME50",
    "currency": "EUR",
    "valueCents": 5000,
    "status": "active",
    "remainingCents": 5000,
    "expiresAt": "2023-11-07T05:31:56Z"
  }
}