Merging Apple Music cassettes on Mac mini

Hi, just bought a Mac mini and adding my cassettes I have copied on Apple Music. Before using iTunes I would drop side A and side B in iTunes, select both files, right click, get info, type in the album name, artist and add the cover image and then they would merge together like a album.

I can't seem to do this in apple music, Does any one have any suggestions?

Cheers

[Re-Titled by Moderator]