MainWindow.xaml

<Window
    x:Class="SystemTrayWinUI3.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:SystemTrayWinUI3"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">
    <Window.SystemBackdrop>
        <MicaBackdrop />
    </Window.SystemBackdrop>
    <Grid>
        <NavigationView 
            x:Name="NavView"
            PaneDisplayMode="Left"
            IsBackButtonVisible="Collapsed"
            SelectionChanged="NavView_SelectionChanged">

            <NavigationView.MenuItems>
                <NavigationViewItem Content="Home" Icon="Home" Tag="home"/>
            </NavigationView.MenuItems>

            <NavigationView.FooterMenuItems/>

            <Frame x:Name="RootFrame"/>
        </NavigationView>
    </Grid>
</Window>