Outlook (and other Microsoft 365 apps) has a great feature that shows users' LinkedIn profiles - but only if the user has connected their Microsoft account to LinkedIn.
❌ Figure: Bad example - LinkedIn profile is not connected to a Microsoft account
✅ Figure: Good example - LinkedIn profile is connected to a Microsoft account
Figure: Click the blue LinkedIn logo
Figure: Sign in to LinkedIn
Note: If your Microsoft account is already connected, you'll see your LinkedIn profile here instead.
You can also check this within LinkedIn. Go to LinkedIn | Settings | Account Preferences | Account Management | Microsoft, and view your account connection.
Figure: Microsoft account connected
See also: Microsoft's Support page on this topic