Open Terminal on your Mac.

Generate a new key:

ssh-keygen -t ed25519 -C "your_username@lengau"

Press Enter to accept the default file location.

Keep the private key safe in:

~/.ssh/id_ed25519

Show your public key:

cat ~/.ssh/id_ed25519.pub

If you generated the key on your computer, copy the contents of your public key file (the file name with extension .pub), paste it into the text box on the ssh-keys page and click on the “Add SSH key” button.