How can I restore Outlook email folders from Time Machine backup

My user's account on his iMac became corrupted. I created a new account for him. I was able to restore all his data except his Outlook email. I tried copying his /Users/<username>/Library/Group Container/UB*****.Office folder from Time Machine to his new account. His folders are not showing up when he opens Outlook. I go to his /Users/<username>/Library/Group Container/UB*****.Office/Outlook/Outlook 15 Profiles/Main Profile/ Data/Messages/255 directory. I right-click on one of the files, and select open with the Outlook application, it does show the actual email message.

So, the messages are there, but the folders and messages don't show up in his Outlook. Am I doing something out of order? He is using Outlook 16.78 on Mac OS 13.6.