Zulip node can not update user for "is_guest"

I tested zulip node with option update user for is_guest, but it seems failed.

  "nodes": [
      "parameters": {
        "resource": "user",
        "operation": "update",
        "userId": "={{$node[\"Find contact\"].json[\"app_user_id\"]}}",
        "additionalFields": {
          "isGuest": true
      "name": "Guest role",
      "type": "n8n-nodes-base.zulip",
      "typeVersion": 1,
      "position": [
      "credentials": {
        "zulipApi": "Zulip - working24.net"
  "connections": {}

Hey @cmdntd987,

Did you get an error? If yes, can you please share what error you received? I am changing this to a question since it seems more of a bug than a feature request :slight_smile: