SwiftUI Add top line to TabBar

How can I add a line/divider on the top of my TabBar for adding some kind of a splitter between my view and TabBar?

I forgot that I have added this code for making the TabBar completely white. But my shadow color was white, so I just changed it to Gray

extension UITabBarController {
override open func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    let appearance = UITabBarAppearance()
    appearance.configureWithOpaqueBackground()

    appearance.backgroundColor = .white
    appearance.shadowImage = UIImage()
    appearance.shadowColor = .gray

    appearance.stackedLayoutAppearance.normal.iconColor = .black
    appearance.stackedLayoutAppearance.normal.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.black]

    self.tabBar.standardAppearance = appearance
}

}