I have managed to use the following code to sync my google sheets to calendar but I would also like it to automatically update the events on a calendar calendar after I edit the sheets for an existing event. Many thanks for your help.
This is the code I have now :

function createCalendarEvent(Bookings) {
  const calendarId = "[email protected]";
  let communitycalendar = CalendarApp.getCalendarById(calendarId);
  let sheet = SpreadsheetApp.getActiveSheet();
  let schedule = sheet.getDataRange().getValues();
  schedule.splice(0, 2);

  const events = {};
  let pageToken = "";
  do {
    const {items, nextPageToken} = Calendar.Events.list(calendarId, {maxResults: 2500, pageToken});
    if (items.length > 0) items.forEach(o => events[o.summary] = true);
    pageToken = nextPageToken || "";
  } while (pageToken);
  schedule.forEach(function (entry) {
    if (!events[entry[0]]) {
      communitycalendar.createEvent(entry[0], entry[5], entry[6], {description: ''+entry[2]+','+entry[8]+'',});
    }
  });
}

test sheet

at the moment it creates the event but it doesnt update events if they are changed on sheets- it only adds new events.