sudo snap remove --purge firefox
sudo add-apt-repository ppa:mozillateam/ppa -y
echo -e "Package: firefox*\nPin: release o=LP-PPA-mozillateam-ppa\nPin-Priority: 550\n\nPackage: firefox*\nPin: release o=Ubuntu\nPin-Priority: -1" | sudo tee /etc/apt/preferences.d/99-mozillateamppa
sudo apt update
sudo apt install firefox-esr -y
# check where did you download the firefox
apt-cache policy firefox-esr