Flutter GoogleMapsAPI - Change Route with Tap on InfoWindow

I am pretty new to Flutter and I am trying to build an App based on GoogleMaps. Now I added multiple markers and when you tap them the first time a info window pops up. Then, after tapping the info window, I want to change route to another screen, which then includes the description of the place etc. However, I am struggling now with making it possible to change route after tapping the infowindow, meaning nothing happens when I tap it.

Is it possible to use the 'OnTap' function on the infowindow? I'm happy for any solutions.

My current code for the marker section:

markers.add(Marker( //add first marker
    markerId: MarkerId(showLocation.toString()),
    position: showLocation, //position of marker
    infoWindow: InfoWindow( //popup info
      title: 'Marker Title First ',
      snippet: 'My Custom Subtitle',
      onTap: () {
        Navigator.push(
            context,
            MaterialPageRoute(builder: (context) => SecondScreen()),
        );
      },
    ),
    icon: BitmapDescriptor.defaultMarker, //Icon for Marker
  ));

I just found a supposedly working solution on this problem (Problem with google_maps_flutter, marker onTap(){} doesn't work), however, I guess due to the implementation of null safety it is not working anymore, since I had to initialize the field 'BuildContext'. I did so using 'late' before it, but it still does not work.

We found the problem, I have given multiple markers the same MarkerId. After I changed it, it worked fine. Sorry guys, case closed!