Partly built: part of this depends on a connection or a switch that may not be on for your account yet. The article says which part.
After surgery or treatment of the head, neck or throat a person may be unable to speak for a time; typing and tapping phrases give a voice at once, and the cloned voice can be recorded before treatment where that is possible. The mode's own library is not built yet.
The condition page on the public site tells the full story and ends with the way to create an account.