In the New Outlook for Windows, you cannot directly create public folder calendars. However, you can view and access existing public folder calendars by adding them to your Favorites list. Here’s how to do that:
Right-click your account name in Outlook and select Add public folder to Favorites.
- If you don't see this option, ensure that public folders are deployed in your tenant. If they are deployed but the option is missing, ask your administrator to check the Microsoft 365 admin center for troubleshooting. In the public folder hierarchy pane, expand "All Public Folders". Select the public folder you want to add, then click Add Public Folder. Once added, you can access the folder from the Favorites list.
However, to create a public folder calendar in Exchange Online, you'll need to use classic Outlook or the Exchange Admin Center (EAC) to first create the public folder. Afterward, you can access and manage it from the New Outlook by following the steps mentioned above.
For further information, you can check these helpful resources:
https://learn.microsoft.com/en-us/outlook/troubleshoot/user-interface/navigate-to-public-folders-in-new-outlook
https://learn.microsoft.com/en-us/exchange/collaboration-exo/public-folders/use-favorite-public-folders