Hi @LeonardoCT!
I can help you with that: you can generate the public and private key with puttygen if you are using windows or ssh-keygen if you are a linux user. The private key must be in sambanas configuration and the public key should be used in this addon: 
[add-on] HassOS SSH port 22222 Configurator - Home Assistant OS - Home Assistant Community (home-assistant.io).
That is the theory but I can’t make it work 