curl --request PUT \
  --url https://checkout.dintero.com/v1/admin/gateways/payex \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "payex": {
    "url": "https://api.payex.com",
    "payee_id": "<string>",
    "token": "<string>",
    "subsite": "12345789"
  }
}
'

{
  "error": {
    "message": "<string>",
    "code": "<string>",
    "errors": [
      {}
    ]
  }
}