[DEPRECATED] Retrieves a Custom Field

curl --request GET \
  --url https://api.rootly.com/v1/custom_fields/{id} \
  --header 'Authorization: Bearer <token>'

{
  "data": {
    "id": "128",
    "type": "custom_fields",
    "attributes": {
      "slug": "earum-consequatur-vel-reprehenderit",
      "description": "Et modi provident asperiores.",
      "enabled": true,
      "position": 1,
      "updated_at": "2025-09-16T17:11:20.524-07:00",
      "created_at": "2025-09-16T17:11:20.524-07:00",
      "kind": "text",
      "label": "Earum consequatur vel reprehenderit.",
      "shown": [
        "incident_form"
      ],
      "required": []
    },
    "relationships": {
      "options": {
        "data": [
          {
            "id": "4",
            "type": "custom_field_options"
          },
          {
            "id": "5",
            "type": "custom_field_options"
          }
        ]
      }
    }
  }
}