Searching by Catalog Number?

Is it possible to retrieve album metadata in Mp3tag using a catalog number or barcode? I have an album titled 'I am' by Joe Hisaishi, which was released in Japan, but the app's search feature can't seem to find it.

In my opinion, searching by catalog number would be much easier than by album name, as searching by title can sometimes return hundreds of irrelevant results.

Are you asking for a search by catalog number for the external source Discogs?

For your search you could use the Menu 'Tag Sources' -> 'Discogs Artist + Album' -> Artist: Joe Hisaishi, Album: I Am, and you would get only 3 matches.
But if you really prefer to seach by catalognumber, then you could follow the advice in Searching Discogs by Barcode or Catalognumber

Have a go at this