Get downloadable backups

Example response

{
  "environment": {
    "display_name": "MyEnvironment",
    "downloadable_backups": [
      {
        "id": "1915fa3a-7ef4-4766-806d-71104be7deb0",
        "created_at": 1665382600770,
        "download_link": "https://example.com",
        "expires_at": 1665382600770,
        "is_generation_in_progress": true
      }
    ]
  }
}