Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
When updating my Microsoft Office package I lost the option of a FAVOURITE file in list of files
How do I reinstall this option in my Outlook viewing file
Are you specifically referring to the favorites in the Folder Pane in Outlook?
If you have the new Outlook, go to Settings > Mail > Folder pane and click to select "Show favorites."
Note that you won't actually see any favorites in the folder pane unless you selected some of your folders as favorites. You can right-click items and choose Add to favorites.