为什么我无法连接到Exchange？

Question

无法连接到Exchange：401客户端错误：未经授权的网址：https://outlook.office365.com/EWS/Exchange.asmx

from pyexchange import Exchange2010Service, ExchangeNTLMAuthConnection
from pytz import timezone
from datetime import datetime
URL = u'https://outlook.office365.com/EWS/Exchange.asmx'
USERNAME = u'user@abc.com'
PASSWORD = u"password"

# Set up the connection to Exchange
connection = ExchangeNTLMAuthConnection(url=URL,
                                    username=USERNAME,
                                    password=PASSWORD)

service = Exchange2010Service(connection)

# List all events from date to date
calendar_list = service.calendar().list_events(
    start=timezone('Europe/Amsterdam').localize(datetime(2020, 7, 1)),
    end=timezone('Europe/Amsterdam').localize(datetime(2020, 10, 30)),
    details=True
)

for event in calendar_list.events:
    print("{start} ------ {stop} ------ {subject}".format(
        start=event.start,
        stop=event.end,
        subject=event.subject
    ))

感谢您的帮助