MainWindow.xaml

<Window x:Class="TMac.WebView2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
        xmlns:wpf="clr-namespace:Microsoft.Web.WebView2.Wpf;assembly=Microsoft.Web.WebView2.Wpf"
        mc:Ignorable="d"
        Title="MainWindow" 
        Height="450" 
        Width="800">
    
    <Grid>
        <TabControl
            x:Name="tabs">
            
            <TabItem Header="Welcome">
                <Grid>
                    <TextBlock>Hello!</TextBlock>
                </Grid>
            </TabItem>

            <TabItem Header="Content">
                <Grid
                    x:Name="webHost">
                    <wpf:WebView2
                        x:Name="browser"
                        />
                </Grid>
            </TabItem>
        </TabControl>
    </Grid>
</Window>