How to trigger a function when user taps on google map markers - Flutter

How can we execute a function for example _markerPressed() in google map when user taps on a marker?

I dont want to show a popup I know its possible using infoWindow. I want to, for example open a card on screen.

I've tried the onTap: and onLongPress: functions but it's only working while tapping on the map not the markers.

Thank you in advance

 final Marker marker = Marker(
          markerId: markerId,
          position: LatLng(
            center.latitude + sin(_markerIdCounter * pi / 6.0) / 20.0,
            center.longitude + cos(_markerIdCounter * pi / 6.0) / 20.0,
          ),
          infoWindow: InfoWindow(title: markerIdVal, snippet: '*'),

          onTap: (){
             //TODO: show your card
           },

          onDragEnd: (LatLng position) => _onMarkerDragEnd(markerId, position),
          onDrag: (LatLng position) => _onMarkerDrag(markerId, position),
        );

https://github.com/flutter/plugins/blob/master_archive/packages/google_maps_flutter/google_maps_flutter/example/lib/place_marker.dart