Introduction
Similar to AWS EC2 login method, clients use SSH login with .pem file.
Steps
(Client) Create SSH key pair
## (Option 1) Use RSA 4096 bits
$ ssh-keygen -P "" -t rsa -b 4096 -m PEM -f <KeyName>
## (Option 2) Use Ed25519
$ ssh-keygen -P "" -t ed25519 -m PEM -f <KeyName>