guard let settingsUrl = URL(string: UIApplication.openSettingsURLString) else {
    return
}
if UIApplication.shared.canOpenURL(settingsUrl)  {
    if #available(iOS 10.0, *) {
        UIApplication.shared.open(settingsUrl, completionHandler: { (success) in
        })
    }
    else  {
        UIApplication.shared.openURL(settingsUrl)
    }
}