ssh
Generate a ssh key
# use 'ed25519' or 'rsa' for encryption algorithm type
$ ssh-keygen -t ed25519 -C "Full Name <email>"
Push and Pull code from GitHub and GitLab via SSH
After you have added your local ~/.ssh/id_ed25519.pub
key file to GitHub/GitLab, test the connection
$ ssh -T git@github.com
Verify that you can clone a repository with git via ssh
$ git clone git@github.com:radavis/ubuntu-for-development.git
# generally...
$ git clone git@github.com:username/repository.git