SwiftUI: How do I access a controller from within a coordinator (MKMapView delegate) inside a UIViewRepresentable?

Question

Edit:

MapViews have the ability to show locations by adding pins (or custom views) to the map. I am attempting the simplest version of customization, where I am just trying to replace the default popup view (Title, Subtitle, Info symbol (i with a circle around it)) with a custom view.

Using a MKMapView from SwiftUI requires using a UIViewRepresentable class with a coordinator to handle its delegate, because MKMapView is a UIKit class, not a SwiftUI struct.

In a UIViewController, I could add a view (or a tableviewcontroller's main view even) as a subview to the annotationView. My question is how to do that using a native SwiftUI struct View.

I am trying to add a custom detailCalloutAccessoryView to a MKPinAnnotation (MKAnnotationView)

  func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {

        var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier) as? MKPinAnnotationView
          if annotationView == nil {
            annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
            addDropDown(annotationView: annotationView)

}

Here's are two attempts at writing addDropDown():

      func addDropDown(annotationView: UIView?) {
             guard let annotationView = annotationView as? MKPinAnnotationView else { return }

// This is a UIKit UITableViewController Instance
            let tvc = RandomCapitalDropDown(nibName: nil, bundle: nil)
            annotationView.addSubview(tvc.view)

// error: Cannot convert value of type 'MKPinAnnotationView' to expected argument type 'UIViewController?'
            tvc.didMove(toParent: annotationView)
            tvc.view.leadingAnchor.constraint(equalTo: annotationView.leadingAnchor).isActive = true
            tvc.view.trailingAnchor.constraint(equalTo: annotationView.trailingAnchor).isActive = true
            tvc.view.topAnchor.constraint(equalTo: annotationView.topAnchor).isActive = true
            tvc.view.bottomAnchor.constraint(equalTo: annotationView.bottomAnchor).isActive = true
        }

// This is for a SwiftUI Struct called `PinDropDown`
        func addDropDown(annotationView: UIView?) {
            guard let annotationView = annotationView as? MKPinAnnotationView else { return }

            let child = UIHostingController(rootView: PinDropDown(gameMode: .byContinent(continent: 0)))
            child.view.translatesAutoresizingMaskIntoConstraints = false
            child.view.frame = parent.view.bounds
            // parent is UIViewRepresentable, so there is no view - this won't work
            parent.view.addSubview(child.view)
            // same issue
            parent.addChild(child)
        }

I have reviewed: SwiftUI UIViewRepresentable and Custom Delegate and Access controller method from inside a model and How to find the frame of a swiftui uiviewrepresentable none of these answered my question.