I understand I have my bootstrapper as it was etc. I thought the solution was to register the Composition Container so I could access it via the ServiceLocator later in my ViewModel? Then I could compose the type when I have the required data to.
Therefore I wanted to know how to register the Composition Container in this ConfigureContainer method.
So in my viewmodel I can do this:
var container = ServiceLocator.Current.GetInstance(CompositionContainer);
and then compose my component. I was just confused with how to do the
"register the Composition Container, by overriding the ConfigureContainer’s method in the Boostrapper" part.