How To Restrict Signature Pad(Wacom Intuous M) Pen Access only Inside Canvas other than Accessing the Whole Window in a WPF Application

Question

When I start to draw signature on signature pad (Wacom intuous M tablet) it should only access the canvas to draw the signature, but it is accessing the whole system maybe because I downloaded the driver of Wacom so I only want the pen to access the Canvas when I run the WPF Application

<Canvas x:Name="signatureCanvas" Background="White" 
        MouseDown="SignatureCanvas_OnMouseDown"  
        MouseMove="SignatureCanvas_OnMouseMove"    
        MouseUp="signatureCanvas_MouseUp" 
        SizeChanged="signatureCanvas_SizeChanged" Margin="30,20,30,49" />

Canvas Pad For Signature

I tried using mouse events so that it draws a signature on canvas:

    private bool isDrawing = false;
    private System.Windows.Point startPoint; 
    
    private void SignatureCanvas_OnMouseDown(object sender, MouseButtonEventArgs e)
    {
        isDrawing = true;
        startPoint = e.GetPosition(signatureCanvas);
    }

    private void SignatureCanvas_OnMouseMove(object sender, MouseEventArgs e)
    {
        if (isDrawing)
        {
            Line line = new Line
            {
                Stroke = System.Windows.Media.Brushes.Black,
                StrokeThickness = 2.5,
                X1 = startPoint.X,
                Y1 = startPoint.Y,
                X2 = e.GetPosition(signatureCanvas).X,
                Y2 = e.GetPosition(signatureCanvas).Y
            };
            startPoint = e.GetPosition(signatureCanvas);
            signatureCanvas.Children.Add(line);
        }
    }

    private void signatureCanvas_MouseUp(object sender, MouseButtonEventArgs e)
    {
        isDrawing = false;
    }