curl --request GET \
  --url https://api.icepanel.io/v1/landscapes/{landscapeId}/versions/{versionId}/diagrams/{diagramId}/thumbnail \
  --header 'Authorization: <authorization>'

{
  "thumbnail": {
    "createdAt": "2023-11-07T05:31:56Z",
    "expires": "2023-11-07T05:31:56Z",
    "handleId": "<string>",
    "id": "<string>",
    "index": 123,
    "modelId": "<string>",
    "name": "<string>",
    "type": "app-diagram",
    "updatedAt": "2023-11-07T05:31:56Z",
    "url": "<string>"
  }
}