Office 365 'Create Event' Rest API is giving error - node.js

Question

I am new user on stackoverflow as well as in office 365 development using node.js.
I am successfully getting User(my own office 365 account) mails,calendar events using this tutorial (https://dev.outlook.com/RestGettingStarted/Tutorial/node)
but when i am trying to Create an Event in my calender it gives me below error
"{"error":{"code":"ErrorAccessDenied","message":"Access is denied. Check credentials and try again."}}"
Please provide me suggestions on the same.
Below is the code for creating event which i copied from [https://msdn.microsoft.com/office/office365/APi/calendar-rest-operations#CreateEvents] here
function createEvent(response, request) {
var cookieName = 'node-tutorial-token';
var cookie = request.headers.cookie;
// if (cookie && cookie.indexOf(cookieName) !== -1) {
console.log("Cookie: ", cookie);
// Found our token, extract it from the cookie value
var start = cookie.indexOf(cookieName) + cookieName.length + 1;
var end = cookie.indexOf(';', start);
end = end === -1 ? cookie.length : end;
var token = cookie.substring(start, end);
console.log("Token found in cookie: " + token);
var event = new outlook.Microsoft.OutlookServices.Event();
event.subject = 'Your Subject';
event.start = new Date("October 30, 2014 11:13:00").toISOString();
event.end = new Date("October 30, 2014 12:13:00").toISOString();
// Body
event.body = new outlook.Microsoft.OutlookServices.ItemBody();
event.body.content = 'Body Content';
event.body.contentType = outlook.Microsoft.OutlookServices.BodyType.Text;
// Location
event.location = new outlook.Microsoft.OutlookServices.Location();
event.location.displayName = 'Location';
// Attendee
var attendee1 = new outlook.Microsoft.OutlookServices.Attendee();
var emailAddress1 = new outlook.Microsoft.OutlookServices.EmailAddress();
emailAddress1.name = "abc";
emailAddress1.address = "abc#abcdt.onmicrosoft.com";
attendee1.emailAddress = emailAddress1;
event.attendees.push(attendee1);
var outlookClient = new outlook.Microsoft.OutlookServices.Client('https://outlook.office365.com/api/v1.0',
authHelper.getAccessTokenFn(token));
outlookClient.me.calendar.events.addEvent(event)
.then(function (response) {
console.log(response._Id);
}, function (error) {
console.log(error);
});
}

Answer 1

Make sure your app has requested for calendar.readwrite permission and you need this to create new events. In the example you followed, your app registered for only Calendar.Read permissions (see below).
You should instead go to https://dev.outlook.com/AppRegistration to register an app with Calendar.ReadWrite permission which is required to create new events.