Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello, I'm Diane, an M365 Apps & Services MVP specializing in Outlook.
The previous instructions were for Windows, not Mac.
Who is your email provider? What type of email account do you have configured in Outlook? POP, IMAP, Outlook.com, or Microsoft Exchange? If IMAP, was it added an Exchange sync account?
Outlook calendar (and contacts) will only sync with iPhone if you use a Microsoft Exchange account (or use Windows and the iCloud addin - which leaves you out).
If you use Gmail, iCloud, yahoo - the account should be added as Microsoft sync account and calendar & contacts will sync between outlook and your server using Microsoft cloud.
Other account types will not sync between outlook and the phone unless you use a sync utility (I don't know if there are any for outlook on mac).