ssh-keygen
git config --global gpg.format ssh
git config --global user.signingKey ~/.ssh/id_ed25519.pub
git config --global commit.gpgsign true
git config --global gpg.ssh.program /usr/bin/ssh-keygen
cat ~/.ssh/id_ed25519.pubThen add your key (the cat above) as both an SSH "Signing" and "Authentication" key (it's in the dropdown when you add a new SSH key.)