Change TabBar backgound

Hi, I have some code as follows:

    public static TabbedPage GetMainPage ()
    {   
        var profilePage = new ContentPage {
            Title = "Profile",
            BackgroundColor = Color.Red,
            Content = new StackLayout {
                Spacing = 20, Padding = 50,
                VerticalOptions = LayoutOptions.Center,
                Children = {
                    new Entry { Placeholder = "Username" },
                    new Entry { Placeholder = "Password", IsPassword = true },
                    new Button {
                        Text = "Login",
                        TextColor = Color.White,
                        BackgroundColor = Color.FromHex("77D065") }}}
        };

        var settingsPage = new ContentPage {
            Title = "Settings",
        };

        var mainPage = new TabbedPage { Children = { profilePage, settingsPage }, BackgroundImage = "Assets/menuBG.png", };

        return mainPage;
    }

I want to change the background of the tab bar that appears with the page names to be menuBG.png. The code above does not work.

How can this be done?