In this video I described ssh configuration and how to generate RSA keys and how to put them into authorized_keys. Step by step explanation.
Script that is doing everything for you:
https://github.com/sysadmin-info/sshd-configurator/blob/main/sshd-config.sh
Genpasswd:
https://github.com/sysadmin-info/sshd-configurator/blob/main/genpasswd