Binding mapy w Xamarin MVVM

Cześć
Mam problem z odpaleniem mapy nie wiem jak mogę zmienić to aby działało.

<d:ExtendedContentPage xmlns:d="clr-namespace:TestApp;assembly=TestApp"
xmlns="http://xamarin.com/schemas/2014/forms" 
xmlns:maps="clr-namespace:Xamarin.Forms.Maps;assembly=Xamarin.Forms.Maps"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
 xmlns:local="clr-namespace:TestApp;assembly=TestApp"
x:Class="TestApp.MapPageView">
<ContentPage.Content>
        <local:CustomMap Text="{Binding customMap}" MapType="Street" WidthRequest="{x:Static local:App.ScreenWidth}" HeightRequest="{x:Static local:App.ScreenHeight}" />

View xaml.cs

    public partial class MapPageView : ExtendedContentPage
{
    public MapPageView()
    {
        InitializeComponent();
        BindingContext = new MapViewModel(Navigation);

    }

Model

 public class CustomMap : Map
    {
        public List<Position> ShapeCoordinates { get; set; }

        public CustomMap()
        {
            ShapeCoordinates = new List<Position>();
        }
    }

ViewModel

public class MapViewModel : BaseViewModel
{

    public CustomMap customMap { set; get; }

    public MapViewModel(INavigation navigation) : base(navigation)
    {
        InitializeMapsPosition();
    }

    private void InitializeMapsPosition()
    {
        customMap.ShapeCoordinates.Add(new Position(52.198913,21.025649));
        customMap.ShapeCoordinates.Add(new Position(52.185499, 21.025425));
        customMap.ShapeCoordinates.Add(new Position(52.189570, 21.057992));
        customMap.ShapeCoordinates.Add(new Position(52.213227, 21.043427));

        customMap.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(52.237244, 21.025585), Distance.FromKilometers(5.0)));
    }

Position 9:21. Cannot assign property "Text": Property does not exists, or is not assignable, or mismatching type between value and property