Step 1.) Upgrade to Debian 11 first
The process to go to Debian 12 is not as smooth as 11, when trying to upgrade from Debian 10. In fact, it doesn't work directly, so you'll first need to follow this guide to update to Debian 11, reboot and come back here if successful.
Step 2.) Update sources.list
Update your /etc/apt/sources.list like this:
deb http://........
i337 Canada on Bell is hard to root or even install TWRP
Installed TWRP from Odin and my computer gave me the bluescreen at the end but it seemed to be successful (after ODIN said reset).
TWRP mode does not seem to enter, instead you get the Android recovery mode with Volume up + Home
http://galaxys4root.com/galaxy-s4-root/how-to-root-att-or-verizon-galaxy-s4-on-android-4-4-2/
1.)........