How can I use GScript to search for all my series appointments and control the output so that only the appointment for which the series appointment has been set is displayed?

I have already created a script, but all appointments are always displayed, but only the “setting appointment” should be displayed.

Where am I making a mistake – or who can show me an example of where I’m stuck?

Thanks

function getRecurringEvents() {
  var calendar = CalendarApp.getDefaultCalendar();
  var now = new Date();
  var oneYearFromNow = new Date(now.getFullYear() + 1, now.getMonth(), now.getDate());

  var events = calendar.getEvents(now, oneYearFromNow);
  var recurringEvents = events.filter(function(event) {
    return event.isRecurringEvent();
  });

  for (let i = 0; i < recurringEvents.length; i++) {
    Logger.log(recurringEvents[i].getTitle());
  } 
}