The first question is, what contact details do you want? Is it just what is reported for "Contact" on the Node Details widget? That info is found in the database and can be used.
If you want other contact details in the widget, you'll want to be sure we are polling it in the first place so that it's in the database. From there, you should be able to display that information in a modern dashboard. You may have to play around with the format, to find the best way to display it. I'd encourage you to browse through some of the Modern Dashboard forums to get tips on how best to build this widget.
