As there is no related feedback to your post, I rewrote your kind proposal up to my preferable liking (not because of I’m awaiting any relevant feedback either or thinking that what you already posted or I’m (re)posting here is everything needed, but might indeed do, at least in general under PureOS):
- get root by
sudo su - add to the
/etc/apt/sources.list:deb https://ftp.debian.org/debian/ bullseye main non-free - execute
apt-get update - execute
apt-get install debian-archive-keyring - execute
apt-get update - execute
apt-get install firmware-linux-free - execute
apt-get install firmware-misc-nonfree - execute
apt-get install isenkram-cli - execute
isenkram-autoinstall-firmware - remove bullseye entry from
/etc/apt/sources.listor mark it to something like this:##deb https:// …, save/exit.
Thanks, @Dwaff!