Run this command in dom0 to replace firefox.desktop app menu entry with org.mozilla.firefox.desktop for all qubes based on fedora-40-xfce template:
qvm-ls --raw-data --fields NAME,TEMPLATE | grep "|fedora-40-xfce" | awk -F '|' '{print $1}' | xargs -I % sh -c 'qvm-appmenus --get-whitelist % | sed "s/^firefox.desktop$/org.mozilla.firefox.desktop/g" | qvm-appmenus --set-whitelist - %'
You can change fedora-40-xfce with the name of your template if it’s different.