Contacts on Message+ on Windows 10

Is there a solution for this?  The screen to add a new contact flashes for about a half a second.  There is no way to add numbers to new contacts.

I found another question about this.  There were two answers.  The one from VZ provided a link to using Message+ on Anroid.  This is no good, we we're talking about Windows.  The other solution was something about Verizon Cloud, which not everyone has.

So... how do we add new contacts to Message+ on Windows?  It is amazing how buggy such a simple app is.