curl --request GET \
  --url https://api.hubapi.com/crm/v3/property-validations/{objectTypeId}/{propertyName} \
  --header 'Authorization: Bearer <token>'

{
  "results": [
    {
      "ruleArguments": [
        "<string>"
      ],
      "ruleType": "AFTER_DATETIME_DURATION",
      "shouldApplyNormalization": true
    }
  ]
}