https://packages.debian.org/bullseye/xmlcopyeditor
People posted to me , why not just use nano, but I did like xmlcopyeditor when having to change/fix xml for open box years back. It was segfaulting on me in 2016, sid and stable.
Debian bug #839606 I should have reported it fixed a year or two ago. I will in the near future.
But, if you do any work with xml and want a gui, it does work.