Google free / busy calendar

Hello,

I am trying to check availability in a google calendar.

  1. use google calendar free / busy → that works
[
    {
        "kind": "calendar#freeBusy",
        "timeMin": "2024-03-27T09:00:00.000Z",
        "timeMax": "2024-03-27T10:00:00.000Z",
        "calendars": {
            "xxxxxx@gmail.com": {
                "busy": [
                    {
                        "start": "2024-03-27T09:00:00.000Z",
                        "end": "2024-03-27T10:00:00.000Z"
                    }
                ]
            }
        }
    }
]
  1. use a router condition to route to a google calendar create event when the calendar is not busy

  2. create the event when not busy (that works)

Could you help use set a router condition in 2. to let Google Create Event only when this is not busy? Is that possible ? Thank you!