How to get the ItemTapped behavior in Xamarin.Forms Radial Menu when using custom templates

<ContentPage.Resources>

        <ResourceDictionary>

            <OnPlatform x:Key="customfontfamily" x:TypeArguments="x:String" Android="radialmenu_Segoe MDL2 Assets.ttf#Segoe MDL2 Assets" WinPhone="radialmenu_Segoe_MDL2_Assets.ttf#Segoe MDL2 Assets" iOS="Segoe MDL2 Assets" />

        </ResourceDictionary>

    </ContentPage.Resources>

    <ContentPage.Content>

        <radialMenu:SfRadialMenu x:Name="radial_Menu"

                                 CenterButtonRadius="20"

                                 ItemsSource="{Binding EmployeeCollection}">

            <radialMenu:SfRadialMenu.CenterButtonView>

            <Grid>

                <StackLayout VerticalOptions="Center">

                    <Image Source="search.png"/>

                </StackLayout>

            </Grid>

        </radialMenu:SfRadialMenu.CenterButtonView>

            <radialMenu:SfRadialMenu.ItemTemplate>

                <DataTemplate>

                    <StackLayout VerticalOptions="Center">

                        <Image>

                            <Image.GestureRecognizers>

                                <TapGestureRecognizer  Command="{Binding BindingContext.RadialMenuCommand,Source={x:Reference radial_Menu}, Mode=TwoWay}" CommandParameter="{Binding}" />

                            </Image.GestureRecognizers>

                            <Image.Source>

                                <FontImageSource FontFamily="{StaticResource customfontfamily}" Color="Black" Glyph="{Binding Icon, Mode=TwoWay}" />

                            </Image.Source>

                        </Image>

                    </StackLayout>

                </DataTemplate>

            </radialMenu:SfRadialMenu.ItemTemplate>

        </radialMenu:SfRadialMenu>

    </ContentPage.Content>

</ContentPage>

public class EmployeeModel : INotifyPropertyChanged

    {

        private string icon;

        public string Icon

        {

            get

            {

                return icon;

            }

            set

            {

                icon = value;

                NotifyPropertyChanged(nameof(Icon));

            }

        }

        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")

        {

            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));

        }

        private string employeeName;

        public string EmployeeName

        {

            get { return employeeName; }

            set { employeeName = value; }

        }

    }

    public class EmployeeViewModel

    {

        public ICommand RadialMenuCommand { get; private set; }

        private ObservableCollection<EmployeeModel> employeeCollection = new ObservableCollection<EmployeeModel>();

        public ObservableCollection<EmployeeModel> EmployeeCollection

        {

            get { return employeeCollection; }

            set { employeeCollection = value; }

        }

       public EmployeeViewModel()

        {

            RadialMenuCommand = new Command(RadialItemTapped);

            EmployeeCollection.Add(new EmployeeModel() { Icon = "\uE700", EmployeeName = "Alex" });

            EmployeeCollection.Add(new EmployeeModel() { Icon = "\uE715", EmployeeName = "Lee" });

            EmployeeCollection.Add(new EmployeeModel() { Icon = "\uE85C", EmployeeName = "Ben" });

            EmployeeCollection.Add(new EmployeeModel() { Icon = "\uE88A", EmployeeName = "Carl" });

            EmployeeCollection.Add(new EmployeeModel() { Icon = "\uE779", EmployeeName = "Yang" });

        }

        void RadialItemTapped(object obj)

        {

            var alertResult = Xamarin.Forms.Application.Current.MainPage.DisplayAlert("Message", (obj as EmployeeModel)?.EmployeeName, null, "OK");

        }

    }

}