This article describes how to access and manage your blocked and safe senders lists within Outlook.
See also Managing Blocked/Safe Senders in the Microsoft 365 Outlook Webapp
In the Outlook App while in the Home tab, Select Junk, and Junk Email Options
Select the Block Senders tab at the top and then select Add or Remove to manage the blocked email addresses
Select the Safe Senders tab and select Add or Remove to manage the safe senders
When complete select Apply and OK to close the window.