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.
Paste the text below, substituting in your GitHub email address.
$ 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.
When you’re prompted to “Enter a file in which to save the key,” press Enter. This accepts the default file location.
Enter a file in which to save the key (/home/you/.ssh/id_rsa): [Press enter]
At the prompt, type a secure passphrase. For more information, see “Working with SSH key passphrases”.
Enter passphrase (empty for no passphrase): [Type a passphrase]
Enter same passphrase again: [Type passphrase again]
Adding your SSH key to the ssh-agent
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.
Start the ssh-agent in the background.
$ eval “$(ssh-agent -s)” Agent pid 59566
Add your SSH private key to the ssh-agent. If you created your key with a different name, or if you are adding an existing key that has a different name, replace id_rsa in the command with the name of your private key file.
$ ssh-add ~/.ssh/id_rsa