Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Search your external drive for *.pub files. That is the file extension for Publisher files. If you can't read or see the extensions, then open Folder Options by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, and then clicking Folder Options. Click the View tab. Under Advanced settings, uncheck 'hide extensions for known file type.
If there are no .pub files on the external drive then you apparently did not copy them over from the previous computer.
You didn't happen to use OneDrive or dropbox to sync and save your files in the cloud did you? That would be another place to look.
DavidF