The guide is written for the bare basics. Using SSH to log in to it and execute those commands isn’t covered because in order to actually set it up from the start, you would already have physical access to it. Remote SSH isn’t for everyone and is not required for the installation and configuration of the rpi nor MM².
That said, it will be covered in an upcoming tutorial which covers things like installing pm2 to auto start npm, and remote access. Remote access is different for everyone, there is no fixed way of doing it. My network isn’t the same as yours, or others.