This guide assumes that you have already created an ssh key pair and added your public key to Anvil.
If that’s not the case, you can find useful information on how to do those steps at, for example:
In order for Amoni to know how to use your ssh keys to connect to a remote server (e.g. anvil.works), add the following to your SSH config file (possibly ~/.ssh/config):
Host anvil.works IdentityFile <path to your ssh key>
Depending on the version of openssh you are using, you may also need the following:
Host anvil.works IdentityFile <path to your ssh key> HostkeyAlgorithms +ssh-rsa PubkeyAcceptedAlgorithms +ssh-rsa
See this forum post for more information.