Using Classic Outlook on Windows for personal email, calendar, and contact management
Try uninstalling the new Outlook from Installed Apps in Windows 11 Settings.
If you still can't access the classic Outlook, see https://support.microsoft.com/en-us/office/you-can-t-open-classic-outlook-on-a-new-windows-pc-5c94902b-31a5-4274-abb0-b07f4661edf5.