where I can install the AppArmor application firewall, inside the TVM, the Template VM, correct?
Is their something Qubes specific to take into account or best practices how to isolate apps inside a VM?
Kind Regards
You can take a look at the qubes whonix install instructions, and can use the same method on debian template. https://www.whonix.org/wiki/Qubes/AppArmor
should be added apt-get install apparmor apparmor-utils apparmor-profiles in the template.
And apparmor-easyprof if you want to create your own profiles. refer to a guide on how to use apparmor. You can find the premade profiles in /etc/apparmor.d folder, and aa-enforce (profile name) to enforce them. Some might need some tweaking to work with debian if they don't already work properly, which you can find on debian forums.