Using Siri to automatically add Outlook events to iCal Calendar
I have a solution to display all Outlook Calendar events in the Apple Calendar app.
(Is that what you want?, your question is mixing many things, I have solutions for each of them but what is your real need?)
I will provide screenshots but everything is in French, I hope you can locate things and/or use Google Translate ;)

Open https://outlook.live.com/calendar/0/view/month

See my calendar is empty I added a test event...

Go to settings like that :

Share/Publish the calendar


Copy this link :



Thanks to this link we can go to the Apple Calendar app and subscribe to it.

Open Calendar app and click to something like subscribe to a calendar :


Paste the previous copied link

You can give it a name and a colour, set few settings.


We are done !



As you can see the test event appeared. From now everything that is added/modified/deleted in the Outlook Calendar will be updated and showed here in Apple Calendar app as read only.
P.S. click CMD+R to trigger a refresh of Apple Calendar if needed
EDIT 1:
The solution above works for Outlook, but what if you directly have an Exchange account?
The solution is even better, you can directly add the account in the Apple Calendar app (Menu Calendar &gt; Settings &gt; Accounts. Then tap the add button (bottom left). And finish by login your Exchange account.)