Hello there, I have some issue in my program. I set FlexLayout.AlignItems = center but I want to have one button into layout at the right side. this is my code:

    private void FillPage()
    {
        ListView SpotView = new ListView
        {

            ItemsSource = Spots,
            HeightRequest = 250,
            RowHeight = 50,
            Margin = new Thickness(0, 0, 10, 0),
            ItemTemplate = new DataTemplate(() =>
            {
                Label Text = new Label
                {
                    Text = "Parking spot number ",
                    HorizontalOptions = LayoutOptions.Start,
                    VerticalOptions = LayoutOptions.Center
                };

                Label Number = new Label()
                {
                    TextColor = Color.FromHex("#007AFF"),
                    HorizontalOptions = LayoutOptions.Center,
                    VerticalOptions = LayoutOptions.Center,
                    FontAttributes = FontAttributes.Bold,
                    FontSize = Device.GetNamedSize(NamedSize.Medium, typeof(Label))
                };
                Number.SetBinding(Label.TextProperty, "ParkingSpotNumber");
                return new ViewCell
                {
                    View = new StackLayout
                    {
                        VerticalOptions = LayoutOptions.Center,
                        Margin = new Thickness(20, 0, 0, 0),
                        Children =
                        {
                            new Grid(){
                                Children =
                                {
                                    Text,
                                    Number
                                }
                            }
                        }
                    }
                };
            })
        };



        Button RefreshButton = new Button()  // this button here
        {
            Text = "Refresh",
            Margin = new Thickness(0, 0, 40, 0),
            Padding = new Thickness(20, 10, 20, 10),
            HeightRequest = 35,
            BackgroundColor = Color.FromHex("#D2E9FC"),


        };
        RefreshButton.Clicked += async (sender, args) => await GetParkingInfo();
        //FlexAlign.SetAlignSelf(RefreshButton, FlexAlignSelf.End);   <---- BAD USSAGE


        // Build the page
        Content = new FlexLayout
        {
            Direction = FlexDirection.Column,
            AlignItems = FlexAlignItems.Center,
            JustifyContent = FlexJustify.SpaceEvenly,
            Children =
            {
                SpotView,
                RefreshButton
            }
        };
    }

I find this: "FlexAlign.SetAlignSelf(RefreshButton, FlexAlignSelf.Center)"but I don't know how to use it.
thanks for your advice.