If you are using the "New Outlook for Windows" desktop app (which looks like the web version), these same steps apply.
Unfortunately, the mobile app does not currently allow you to manage the blocked senders list directly. You must use the web version. how to unblock an email address in outlook
If you use Outlook on the Web or the New Outlook for Windows app, follow these steps: Block or unblock senders in Outlook - Microsoft Support If you are using the "New Outlook for
Microsoft is unifying its interfaces. The "new" Outlook (and the web version) uses a modern, consistent layout. these same steps apply. Unfortunately
The mobile app doesn't have a central "Blocked Senders" list. Instead, you manage blocks directly from an email.