When you need to access your server, there are three ways you can do it:
You already have everything you need to be able to access your site using (1) and (2). However, to access files via sFTP using a user that is restricted to a single site, you first need to setup the user. To setup a user:
The screen will refresh and you can click the sFTP tab again to see the new user. At this point you should be able to log into the server using this user id and password. Your server address is going to be the IPv4 address of the server connecting over port 22.
After you have added your first user, additional sections will appear in the sFTP tab. Each section allows you to perform one of the following actions:
An sFTP user (username) can be assigned to one and only one site. If you try to add the same username to another site, you’ll get an error. This leads to some interesting scenarios. For example, if you add a user to a site, delete the site, re-add a site with the same name, you cannot add that user to the new site. This is because the user already exists (it wasn’t deleted when the first site was deleted – just in case the admin is using the user for other non-wp purposes).