To create SSH key pairs on Mac, the built-in Terminal application is used, which is located in the Utilities folder under Applications.
Start Terminal and run the
ssh-keygen -m PEM -f ~/Desktop/anvil_key. This will create two key
files on your Desktop, one public and one private, which can later be
moved to whatever location you prefer.
A prompt will appear to enter a passphrase. Press Enter twice to continue and create the key without a passphrase.
The command will complete and you will see a message saying the files have been created.
There will now be two key files on your Desktop. The public key is
anvil_key.pub. This public key will later be added to your
Anvil account for SSH access to your instances. The private key is
anvil_key (no .pub extension). Treat the private key file the
same as you would a password. Keep your private key in a secure
location and do not share it with anyone.