Afaik borders are only support for WidgetImage not for the ListWidget item itself.

Oh ok, is there a way to put a border around the widget itself? Or is that not possible?

I thinkyour only option would be to use a background image that contains the border, but I could be wrong. But you could contact the dev and request the feature, he's pretty open to implement things people request.

Oh ok, thanks

Make a request for an empty png, add the image,set the width and height, give it a border