Hi, you can sync it entering in the calendar app and follow the instruction

otherwise

In the Odoo database, open to the Calendar module, and click the Outlook sync button on the right-side of the page, beneath the monthly calendar. The synchronization is a two-way process, meaning that events are reconciled in both accounts (Outlook and Odoo) 

https://www.odoo.com/documentation/17.0/it/applications/productivity/calendar/outlook.html#:~:text=all%20event%20attendees.-,Sync%20Odoo%20Calendar%20and%20Outlook,accounts%20(Outlook%20and%20Odoo).