Using Petite Vue with Windows UMP WebView control

When using Petite Vue with the Windows UMP WebView control, it throws an exception PetiteVue is not defined. The same code works in Chrome and Edge browsers.

<Page
x:Class="UMP_Browser.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:UMP_Browser"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

<Grid>
    <WebView x:Name="WebViewControl" Source="**https://v21y4.csb.app/global-scope-petite.html**" />
</Grid>
</Page>

Is there some setting on the UMP WebView control that needs to be set? I am using the latest Windows SDK and Visual Studio.

To see the exception in the WebView, you can use an exception handler like this

 try {
      PetiteVue.createApp(data).mount('#app');
 }
 catch (err) {
      document.getElementById("demo").innerHTML = err.message;
 }

Thanks, Ash

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