Generate a keypair to be used at example.com:
$ ssh-keygen -t ed25519 -f ~/.ssh/id_ed25519_example_com -C "your@email.com"
$ ssh-keygen -t rsa -b 4096 -f ~/.ssh/id_rsa_example_com -C "your@email.com"Note: your email may or may not be on example.com.
Please add -q -N '' at the end of the shell command above if you want to
generate a key without a passphrase non-interactively.
Check that the passphrase works:
$ ssh-keygen -y -f ~/.ssh/id_ed25519_example_comConnect to a host
$ ssh -i ~/.ssh/id_ed25519_example_com <username>@<hostname_or_ip>