root@debian:~# cat /etc/apt/sources.list
# deb cdrom:[Debian GNU/Linux 12.0.0 _Bookworm_ - Official amd64 DVD Binary-1 with firmware 20230610-10:23]/ bookworm main non-free-firmware
deb https://deb.debian.org/debian/ bookworm main non-free-firmware
deb-src https://deb.debian.org/debian/ bookworm main non-free-firmware
deb https://deb.debian.org/debian/ bookworm-security main non-free-firmware
deb-src https://deb.debian.org/debian/ bookworm-security main non-free-firmware
# bookworm-updates, to get updates before a point release is made;
# see https://www.debian.org/doc/manuals/debian-reference/ch02.en.html#_updates_and_backports
deb https://deb.debian.org/debian/ bookworm-updates main non-free-firmware
deb-src https://deb.debian.org/debian/ bookworm-updates main non-free-firmware
root@debian:~#
root@debian:~# ls -l /etc/apt/sources.list.d/
total 0
root@debian:~#