Enabling no-subscription repositories

Prepare

Launch shell from hypervisor

This should provide root shell (priviledged access), if not elevate

sudo su

Ensure Internet connectivity

ping download.proxmox.com

apt update
apt install tmux

tmux

On Debian v13 (trixie)

mv /etc/apt/sources.list.d/pve-enterprise.sources  /root
mv /etc/apt/sources.list.d/ceph.sources            /root

Which version of Debian is running?

hostnamectl | grep -i debian

Create new file

nano /etc/apt/sources.list.d/pve-no-subscription.list

repos

# for Debian GNU/Linux 13 (trixie)
deb http://download.proxmox.com/debian/pve trixie pve-no-subscription

close editor, confirm changes (save)

CTRL+X, y

Adjust Debian repos

nano /etc/apt/sources.list.d/debian.sources

verify repos

#
# for Debian GNU/Linux 13 (trixie)
#

Types: deb
URIs: http://deb.debian.org/debian/
Suites: trixie trixie-updates
Components: main contrib non-free-firmware
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg

Types: deb
URIs: http://security.debian.org/debian-security/
Suites: trixie-security
Components: main contrib non-free-firmware
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg

Close editor, save