CustomAnnotation or CustomModifier MVVM SciChartGroup ItemTemplate

Hi,

I’m looking to draw a BoxAnnotation onto a SciChartGroup ItemTemplate SciStockChart where the user will left mouse click, drag to define the size and releases to create the BoxAnnotation.

How should I go about doing this? Should I be looking at CustomModifiers or CustomAnnotations?

Any pointers will be very helpful

Thanks

David