I have an issue in Outlook Calendar for create events?

import msal
import requests
import datetime
class OutlookAuth:
    def __init__(self, client_id, client_secret, tenant_id, user_id):
        """
        :param client_id: Azure app client ID
        :param client_secret: Azure app client secret
        :param tenant_id: Azure tenant ID
        :param user_id: The email or user principal name of the calendar owner
        """
        self.client_id = client_id
        self.client_secret = client_secret
        self.tenant_id = tenant_id
        self.user_id = user_id
        self.scope = ["https://graph.microsoft.com/.default"]
        self.authority = f"https://login.microsoftonline.com/{tenant_id}"
        self.app = msal.ConfidentialClientApplication(
            client_id=self.client_id,
            authority=self.authority,
            client_credential=self.client_secret
        )
        self.access_token = self.get_access_token()
    def get_access_token(self):
        print("Requesting token with client_id:", self.client_id)
        result = self.app.acquire_token_for_client(scopes=self.scope)
        if "access_token" in result:
            return result["access_token"]
        else:
            print("Full error result:", result)
            raise Exception(f"Auth error: {result.get('error_description', 'Unknown error')}")
    def get_calendar_events(self):
        url = f"https://graph.microsoft.com/v1.0/users/{self.user_id}/events"
        headers = {
            "Authorization": f"Bearer {self.access_token}",
            "Content-Type": "application/json"
        }
        response = requests.get(url, headers=headers)
        if response.status_code == 200:
            return response.json().get('value', [])
        else:
            print(f"Error fetching events: {response.status_code}")
            print("Get_Calendar_Response:", response.text)
            return []
    def time_conflicts(self, new_start_time, new_end_time):
        events = self.get_calendar_events()
        if not events:
            return False
        for event in events:
            existing_start = datetime.datetime.fromisoformat(event["start"]["dateTime"])
            existing_end = datetime.datetime.fromisoformat(event["end"]["dateTime"])
            if (new_start_time < existing_end and new_end_time > existing_start):
                return True
        return False
    def create_event(self, start_time, end_time, subject="Room Booking"):
        url = f"https://graph.microsoft.com/v1.0/users/{self.user_id}/events"
        headers = {
            "Authorization": f"Bearer {self.access_token}",
            "Content-Type": "application/json"
        }
        event_data = {
            "subject": subject,
            "start": {
                "dateTime": start_time,
                "timeZone": "Australia/Sydney"
            },
            "end": {
                "dateTime": end_time,
                "timeZone": "Australia/Sydney"
            }
        }
        response = requests.post(url, headers=headers, json=event_data)
        if response.status_code == 201:
            print("Event created successfully")
            return response.json().get("id")
        else:
            print(f"Error creating event: {response.status_code}")
            print("Create_Response:", response.text)
            return None
    def update_event(self, event_id, new_start_time, new_end_time, new_subject=None):
        url = f"https://graph.microsoft.com/v1.0/users/{self.user_id}/events/{event_id}"
        headers = {
            "Authorization": f"Bearer {self.access_token}",
            "Content-Type": "application/json"
        }
        event_data = {
            "start": {
                "dateTime": new_start_time,
                "timeZone": "Australia/Sydney"
            },
            "end": {
                "dateTime": new_end_time,
                "timeZone": "Australia/Sydney"
            }
        }
        if new_subject:
            event_data["subject"] = new_subject
        response = requests.patch(url, headers=headers, json=event_data)
        if response.status_code == 200:
            print("Event updated successfully")
        else:
            print(f"Error updating event: {response.status_code}")
            print("Response:", response.text)
    def delete_event(self, event_id):
        url = f"https://graph.microsoft.com/v1.0/users/{self.user_id}/events/{event_id}"
        headers = {
            "Authorization": f"Bearer {self.access_token}",
        }
        response = requests.delete(url, headers=headers)
        if response.status_code == 204:
            print("Event deleted successfully")
        else:
            print(f"Error deleting event: {response.status_code}")
            print("Response:", response.text)
if __name__ == "__main__":
    client_id = 'my client-id'
    client_secret = 'my client secret-id'
    tenant_id = 'my tenant-id'
    user_id = "******@bournecloud.com.au"
    outlook_auth = OutlookAuth(client_id, client_secret, tenant_id, user_id)
    start = "2025-04-25T14:00:00"
    end = "2025-04-25T15:00:00"
    event_id = outlook_auth.create_event(start, end, subject="Hotel Room Booking")
    events = outlook_auth.get_calendar_events()
    print(f"Fetched {len(events)} events.")