Bookworm with optional repos

cat <<EOF> /etc/apt/sources.list
deb http://deb.debian.org/debian                bookworm                        main contrib non-free non-free-firmware
deb http://deb.debian.org/debian                bookworm-updates                main contrib non-free non-free-firmware
deb http://deb.debian.org/debian-security/      bookworm-security               main contrib non-free non-free-firmware

# *** Optional ***
#deb http://deb.debian.org/debian                bookworm-backports              main contrib non-free non-free-firmware
#deb http://deb.debian.org/debian                bookworm-backports-sloppy       main contrib non-free non-free-firmware
#deb http://deb.debian.org/debian                bookworm-proposed-updates       main contrib non-free non-free-firmware
EOF

Bullseye with optional repos

cat <<EOF> /etc/apt/sources.list
deb http://deb.debian.org/debian                bullseye                        main contrib non-free
deb http://deb.debian.org/debian                bullseye-updates                main contrib non-free
deb http://deb.debian.org/debian-security/      bullseye-security               main contrib non-free

# *** Optional ***
#deb http://deb.debian.org/debian                bullseye-backports              main contrib non-free
#deb http://deb.debian.org/debian                bullseye-backports-sloppy       main contrib non-free
#deb http://deb.debian.org/debian                bullseye-proposed-updates       main contrib non-free
EOF

Buster with optional repos

cat <<EOF> /etc/apt/sources.list
deb http://deb.debian.org/debian                buster                        main contrib non-free
deb http://deb.debian.org/debian                buster-updates                main contrib non-free
deb http://deb.debian.org/debian-security/      buster-security               main contrib non-free

# *** Optional ***
#deb http://deb.debian.org/debian                buster-backports              main contrib non-free
#deb http://deb.debian.org/debian                buster-backports-sloppy       main contrib non-free
#deb http://deb.debian.org/debian                buster-proposed-updates       main contrib non-free
EOF