Use Debian on UTM to create another Debian.
Steps
sudo apt update sudo apt install build-essential debootstrap live-build
Then
sudo debootstrap stable vdh http://deb.debian.org/debian
Then go into build so that you can install software:
sudo chroot vdh /bin/bash
Then install applications, e.g.:
apt update ssh wget ncdu mc qemu-guest-agent spice-vdagent virt-manager spice-webdavd network-manager-openvpn-gnome default-jre
Next, use the lb commands.
More information:
https://wiki.debian.org/DebianInstaller/Preseed
https://live-team.pages.debian.net/live-manual/html/live-manual/examples.en.html
https://www.reddit.com/r/debian/comments/4mukjm/can_you_create_an_iso_using_debootstrap/
https://l3net.wordpress.com/2013/09/21/how-to-build-a-debian-livecd/
https://gist.github.com/linzheming/205752af251ef2160fcfa2ee51a83287
https://github.com/EHowardHill/Debian-Bootstrap-Script/blob/main/setup-debian.sh
https://gist.github.com/ravecat/63a0d49014b6187bebc68cf855d55a83