How to save diagram with image as Pdf?

<Grid>
<Grid.RowDefinitions>
    <RowDefinition Height="Auto"/>
    <RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<sfDiagram:SfDiagram  VerticalOptions="FillAndExpand" HeightRequest="500" x:Name="diagram" />
<Button Text="Save Diagram as PDF" HeightRequest="50" Grid.Row="1" Clicked="Button_Clicked"/>
</Grid>

//Define the data template to a node.
var template = new DataTemplate(() =>
{
      StackLayout stacklayout = new StackLayout();
      stacklayout.WidthRequest = 200;
      stacklayout.HeightRequest = 300;
      stacklayout.BackgroundColor = Color.Transparent;
      stacklayout.VerticalOptions = LayoutOptions.FillAndExpand;
      stacklayout.HorizontalOptions = LayoutOptions.FillAndExpand;
      stacklayout.Orientation = StackOrientation.Vertical;
      Image image = new Image();
      image.BackgroundColor = Color.Transparent;
      image.WidthRequest = 200;
      image.HeightRequest = 200;
      image.Aspect = Aspect.AspectFit;
      image.Source = "https://media.geeksforgeeks.org/wp-content/cdn-uploads/gfg_200x200-min.png";
      stacklayout.Children.Add(image);
 
      Label label = new Label()
      {
            TextColor = Color.Red,
            Text = "Image",
            FontSize = 12,
            HorizontalOptions = LayoutOptions.CenterAndExpand,
            VerticalOptions = LayoutOptions.CenterAndExpand
      };
      stacklayout.Children.Add(label);
      return stacklayout;
});
//Initialize a node with a template.
Node node = new Node() { Width = 200, Height = 300, OffsetX = 0, OffsetY = 0, Template = template };
node.Style.Brush = new SolidBrush(Color.Transparent);
node.Style.StrokeBrush = new SolidBrush(Color.Transparent);
diagram.AddNode(node);