Adding Calendar Event using Microsoft Graph API - microsoft-graph-api

Question

I am trying to create an event in a calendar from a Powershell script. It needs to add the calendar event to the organizer's calendar and then to a list of attendees. Below is what I am sending in the body of the request.
{
"subject": "Let's go for lunch",
"IsOrganizer": "true",
"body": {
"contentType": "HTML",
"content": "Does noon work for you?"
},
"start": {
"dateTime": "2020-08-31T12:00:00",
"timeZone": "Pacific Standard Time"
},
"end": {
"dateTime": "2020-08-31T14:00:00",
"timeZone": "Pacific Standard Time"
},
"location":{
"displayName":"Harry's Bar"
},
"attendees": [
{
"emailAddress": {
"address":"attendee1#attendeeadress.com",
"name": "Attendee1"
},
"type": "required",
"status": {
"response": "none",
"time": "0001-01-01T00:00:00Z"
}
},
{
"emailAddress": {
"address":"attendee2#attendeeadress.com",
"name": "Attendee2"
},
"type": "required",
"status": {
"response": "none",
"time": "0001-01-01T00:00:00Z"
}
}
],
"organizer":{
"emailAddress":{
"name":"Specific Calendar",
"address":"calendarname#organizerorganization.onmicrosoft.com"
}
},
"allowNewTimeProposals": true
}
It appears successfully on the calendar of the attendees but not on the main organizer's calendar. Can anyone tell me what I am doing wrong and how I can get this to appear on the main organizer's calendar?
Thanks!
UPDATE - This is how I am getting the user token.
$Body = #{
'client_id' = 'my_client_id'
'scope' = 'https://graph.microsoft.com/.default'
'client_secret' = 'my_client_secret'
'grant_type' = 'password'
'userName' = 'calendarname#organizerorganization.onmicrosoft.com'
'password' = 'password'
}
It is now my understanding that this user should be set as the organizer of an event by default.

Answer 1

You can create an event using ROPC flow which gives you the user access token and using it you can call the /events endpoint with your payload as shown below.
POST https://graph.microsoft.com/v1.0/me/calendar/events
If you create an event with this token and give username as calendarname#organization.onmicrosoft.com this will be the organizer of the event.
And you can update 'subject', 'body/content' but you cannot update the event's 'start' and 'end' properties which is already a finished event.