Popover and how to compute 'targetPoint'?

I am trying to use SwiftUI for an iPad app and want to include a button (ellipsis) to access a menu.


I have a Button, displaying the Image(systemName: "ellipsis").


I am trying to understand how to display a new View as a popover tied to the pressed button.


To use Popover, I need a target point, but I don't see how to gain access to this under SwiftUI. Anyone have any clues on this?