1.
distro=$(if echo " bullseye focal impish uma una " | grep -q " $(lsb_release -sc) "; then echo $(lsb_release -sc); else echo focal; fi)
2.
echo "deb [arch=amd64] http://deb.librewolf.net $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/librewolf.list
3.
sudo wget https://deb.librewolf.net/keyring.gpg -O /etc/apt/trusted.gpg.d/librewolf.gpg
4.
sudo apt update
5.
sudo apt install librewolf