how to pass the overlayProps into Panel

How can I pass the styles overlayProps into the Panel component as it is stated in https://developer.microsoft.com/en-us/fluentui#/controls/web/panel

I tried:

<Panel
    overlayProps={{styles:{backgroundColor:'red'}}}
/>

But does not seems to work

The only thing missing from the original source is root, which is the target element in the overlay.

This snippet (full example) shows a Panel with a red overlay. (full example)

const PanelBasicExample: React.FunctionComponent = () => {
  return (
    <div>
      <Panel
        headerText="Sample panel"
        isOpen={true}
        overlayProps={{ className: "foo", styles: { root: { backgroundColor: "red" }}}}
      >
        <p>Content goes here.</p>
      </Panel>
    </div>
  );
};