Retrieves an alert source

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

{
  "data": {
    "id": "48011f76-30e4-4254-bb23-83d9d1b80f51",
    "type": "alert_sources",
    "attributes": {
      "name": "Alert Source 21",
      "source_type": "datadog",
      "status": "setup_incomplete",
      "secret": "6758eba45371df1a9690a76d3d86e83636797ff987dc9bcff886ccf7548e411e",
      "alert_urgency_id": "b77ad884-47f2-445b-bbee-59f62acfe862",
      "created_at": "2025-12-18T18:54:45.977-08:00",
      "updated_at": "2025-12-18T18:54:45.977-08:00",
      "webhook_endpoint": "http://localhost:3001/webhooks/incoming/datadog_webhooks/notify/<TYPE>/<ID>",
      "owner_group_ids": [],
      "alert_source_urgency_rules_attributes": [],
      "alert_source_fields_attributes": [],
      "sourceable_attributes": null,
      "alert_template_attributes": null,
      "resolution_rule_attributes": null
    },
    "relationships": {
      "alert_source_urgency_rules": {
        "data": []
      },
      "alert_source_fields": {
        "data": []
      }
    }
  }
}