Generate a key

ssh-keygen -t ed25519

Config

Set global defaults for all hosts on ${HOME}/.ssh/config.

Host *
     IgnoreUnknown UseKeychain
     UseKeychain yes
     AddKeysToAgent yes
     Compression yes
     PreferredAuthentications publickey
     ServerAliveInterval 60
     TCPKeepalive yes
     # IdentityFile ~/.ssh/id_ed25519

ssh-agent

Add ssh key to ssh-agent

List registered keys

ssh-add -L

References