Makazzz

I did get to install the Mullvad repo on Mint. The thing is they use the “lsb_release -cs” command which give the codename of Mint and not Ubuntu.

But if you use

awk -F= '$1=="UBUNTU_CODENAME" { print $2 ;}' /etc/os-release

It will give the codename for Ubuntu used by Mint.

Try this from the Mullvad instruction with this change :

# Download the Mullvad signing key
sudo curl -fsSLo /usr/share/keyrings/mullvad-keyring.asc https://repository.mullvad.net/deb/mullvad-keyring.asc

# Add the Mullvad repository server to apt
echo "deb [signed-by=/usr/share/keyrings/mullvad-keyring.asc arch=$( dpkg --print-architecture )] https://repository.mullvad.net/deb/stable $(awk -F= '$1=="UBUNTU_CODENAME" { print $2 ;}' /etc/os-release) main" | sudo tee /etc/apt/sources.list.d/mullvad.list

# Install the package
sudo apt update
sudo apt install mullvad-vpn