https://help.github.com/en/articles/connecting-to-github-with-ssh
https://www.ssh.com/iam/password/generator
# list existing keys
$ ls -la ~/.ssh/
# in case you need to generate a new key
$ ssh-keygen -t rsa -b 4096 -C <email>
# start ssh-agent
$ eval "$(ssh-agent -s)"
# add key to agent
$ ssh-add ~/.ssh/id_rsa
# copy the public key
$ xclip -sel clip ~/.ssh/id_rsa.pub
# add public key to GitHub settings
# https://github.com/settings/keys
# test SSH connection
$ ssh -T [email protected]
# list fingerprints of all identitie
$ ssh-add -l
# set origin remote to ssh url in your local repo
$ git remote set-url origin [email protected]:<user>/<repo>.git
# check origin remote url
$ git remote -v
origin [email protected]:<user>/<repo>.git (fetch)
origin [email protected]:<user>/<repo>.git (push)