curl --request GET \
  --url https://api.example.com/api/CustomFields/{entityId}

[
  {
    "id": 123,
    "dbTypeId": 123,
    "agencyName": "<string>",
    "dataType": "<string>",
    "isActive": true,
    "name": "<string>",
    "nameWithoutSpaces": "<string>",
    "usePredefinedValues": true,
    "isSearchable": true,
    "mandatory": true,
    "multiLine": true,
    "editable": true,
    "editableViaGrids": true,
    "numberTypeId": 123,
    "numberTypeName": "<string>",
    "enableDropdownBooleanSearching": true,
    "stringTypeId": 123,
    "stringTypeName": "<string>"
  }
]