AppShell.xaml

<?xml version="1.0" encoding="UTF-8"?>
<FlyoutPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
            xmlns:cr="clr-namespace:Syncfusion.Maui.Core;assembly=Syncfusion.Maui.Core"
			xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
            xmlns:view="clr-namespace:MaApp"
            x:Class="MaApp.AppShell"
            xmlns:mct="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"
            Title="FlyoutPage"
            x:Name="this"
            BindingContext="{x:Reference this}">

    <FlyoutPage.Flyout>
        <ContentPage Title="Menu">
           
        </ContentPage>
    </FlyoutPage.Flyout>

    <FlyoutPage.Detail>
        <NavigationPage>
            <x:Arguments>
                <view:MainPage/>
            </x:Arguments>
        </NavigationPage>
    </FlyoutPage.Detail>

</FlyoutPage>