For Ubuntu 20.04, I have also noticed that both snap installed Chromium and Brave Web browsers fails to work with the
gnome-shell-integration extension. Brave is a derivative of Chromium.
In the case of Brave, this issue is overcome by following Brave's instruction on installing the
.deb versions of the brave-browser and brave-keyring files.
$ sudo apt install apt-transport-https curl
$ sudo curl -fsSLo /usr/share/keyrings/brave-browser-archive-keyring.gpg https://brave-browser-apt-release.s3.brave.com/brave-browser-archive-keyring.gpg
$ echo "deb [signed-by=/usr/share/keyrings/brave-browser-archive-keyring.gpg arch=amd64] https://brave-browser-apt-release.s3.brave.com/ stable main"|sudo tee /etc/apt/sources.list.d/brave-browser-release.list
$ sudo apt update
$ sudo apt install brave-browser
However, the chromium-browser does not have an equivalent
.deb package to overcome this issue. If one does issue the command
sudo apt install chromium-browser,
this command will instead instruct snap to install chromium.
gnome-shell-integration extension does work with Firefox. It is a preinstalled
.deb pkg of Ubuntu 20.04.