HI!
Sorry but what is the field for cover art?
I would like also to include it in the fields I want to keep...
https://docs.mp3tag.de/mapping
And the official standard is http://id3.org/id3v2.3.0#Declared_ID3v2_frames
The help page is not helpful for this question because it does not mention the APIC field, used for an attached picture.
In Mp3tag that field is called PICTURE.
Include this in your list of fields to keep. (eg. ALBUM;ARTIST;COMMENT;GENRE;TRACK;YEAR;PICTURE)