This is the original article on GitHub site.
After you’ve checked for existing SSH keys, you can generate a new SSH key to use for authentication, then add it to the ssh-agent.
If you don’t already have an SSH key, you must generate a new SSH key. If you’re unsure whether you already have an SSH key, check for existing keys.
If you don’t want to re-enter your passphrase every time you use your SSH key, you can add your key to the SSH agent, which manages your SSH keys and remembers your passphrase.
ssh-keygen -t rsa -b 4096 -C "email@example.com"
This creates a new ssh key, using the provided email as a label.
Generating public/private rsa key pair.
Enter a file in which to save the key (/home/you/.ssh/id_rsa): [Press enter]
Enter passphrase (empty for no passphrase): [Type a passphrase] Enter same passphrase again: [Type passphrase again]
Before adding a new SSH key to the ssh-agent to manage your keys, you should have checked for existing SSH keys and generated a new SSH key.
eval "$(ssh-agent -s)" Agent pid 59566