How to create a DropShadow for a SplitView.Pane like in Edge

I am currently trying to create a SplitView.Pane that looks kinda like the edge browser history/favourites pane. Therefore, I need a shadow at the (left) border of my SplitView.Pane.

To create the shadow, I use the DropShadowPanel from the UWP Toolkit. The idea is something like this (doesn't work, of course):

<controls:DropShadowPanel>
    <SplitView.Pane>
        <!--Content-->
    </SplitView.Pane>
</controls:DropShadowPanel>

The shadow should be outside the panel. How do I get this done?

This is how the shadow should look like:

How it should look like

EDIT: The DropShadow should be OUTSIDE the pane. The duplicate-post's answer creates a shadow inside the pane. Unless i miss something there.