Retrieves an alert field

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

{
  "data": {
    "id": "c2881c5a-55d5-4276-bb92-52cf3f1078d7",
    "type": "alert_fields",
    "attributes": {
      "slug": "alert-field-1",
      "name": "Alert Field 1",
      "kind": "custom",
      "created_at": "2026-01-23T22:53:32.761-08:00",
      "updated_at": "2026-01-23T22:53:32.761-08:00"
    }
  }
}