ControlTemlate Command Binding

Microsoft documentation shows how to inherit from a ControlTemplate and use a ContentPresenter.

It shows how to use string properties to populate string bound items in the template. (e.g. HeaderText)

It doesn't show how to do the same with commands. I want to drive the command behavior of a button in the template via the implementing contentpage/viewmodel.

Following the property example, I tried the same with an ICommand but it gets ignored. Meaning, the button isn't executing the provided command. Is commanding not supported?

Example This is in my ControlTemplate, called ApplicationChrome.xaml

                <Label Grid.Row="0"
                   Margin="20,0,0,0"
                   Text="{TemplateBinding HeaderText}"
                   TextColor="White"
                   FontSize="Title"
                   VerticalOptions="Center"/>

                  <Button Grid.Column="0"
                        x:Name="LeftButton"
                        Margin="20,0,0,0"
                        Text="Change Label"
                        TextColor="White"
                        HorizontalOptions="Start"
                        VerticalOptions="Center"
                        Command="{TemplateBinding LeftButtonTemplateCommand}"

The code-behind defines both Bindable Properties

    public static readonly BindableProperty HeaderTextProperty = BindableProperty.Create("HeaderText", typeof(string), typeof(ContentPage), null, BindingMode.TwoWay);
    public string HeaderText
    {
        get => (string)GetValue(HeaderTextProperty);
        set => SetValue(HeaderTextProperty, value);
    }


    public static readonly BindableProperty LeftButtonTemplateCommandProperty = BindableProperty.Create("LeftButtonCommand", typeof(ICommand), typeof(ApplicationChrome), null);

    public ICommand LeftButtonTemplateCommand
    {
        get => (ICommand) GetValue(LeftButtonTemplateCommandProperty);
        set => SetValue(LeftButtonTemplateCommandProperty, value);
    }

My implementing view sets both Bindables

<core:ApplicationChrome xmlns="http://xamarin.com/schemas/2014/forms" 
         xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
         xmlns:d="http://xamarin.com/schemas/2014/forms/design"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:core="clr-namespace:FEOD.Core;assembly=FEOD"
         mc:Ignorable="d"
         HeaderText="FE | Home"
         LeftButtonTemplateCommand="{Binding LeftButtonCommand}"
         x:Class="FEOD.Views.HomeView">

The implementing view's BindingContext is set to it's viewmodel which defines the LeftButtonCommand

    public ICommand LeftButtonCommand { get; private set; }

    private static void OnLeftButtonClicked(object obj)
    {
        var a = 1;
    }

    public HomeViewModel()
    {
        LeftButtonCommand = new Command(OnLeftButtonClicked);
    }

The bound HeaderText displays "FE | Home" just fine. But the bound command never fires OnLeftButtonClicked.

The first parameter of BindableProperty.Create() method has to be "LeftButtonTemplateCommand" not "LeftButtonCommand". The Property name has to exactly match for Binding to work.