Hello Rick,
Is it possible to install Debian Bullseye on a Raspberry Pi 4 (4GB) from a CD/DVD or USB Flash stick or uSDcard?
I don't think so.But you can generate your own image with the vmdb2 tool and this repo: https://salsa.debian.org/raspi-team/image-specs
Or use prebuild images: https://wiki.debian.org/RaspberryPiImages Best regards, Matthias