How to debug/step into Xamarin.Forms source code?

I have seen this article https://shaneneuville.com/xamarin/forms/debugging/2018/02/01/debug-tips.html
but it is not clear for me how this should work and what it meant that "Now you’re ready to step into the source code. Run your project and when you try to step into anything or view the call stack it’ll let you navigate to the files at d:/a/1/s"
Does it mean that we can continue using xamarin.form nuget and step into clone of the source code somehow? if that is the case, how is that linked? Could anyone achieve this what article is telling us?