Badge signature has changed in iOS 18

Hi,

I'm trying to add a badge to a Tab when a certain condition is met. Prior to iOS 18 I could do .badge(showBadge ? "Show" : nil). However, in iOS 18 I'm getting the following error message 'nil' cannot be used in context expecting type 'LocalizedStringKey'.

Right clicking the .badge -> Jump to Definition shows the following

    /// Generates a badge for the tab from a localized string key.
    ///
    /// Use a badge to convey optional, supplementary information about a
    /// view. Keep the contents of the badge as short as possible. The string
    /// provided will appear as an indicator on the given tab.
    ///
    /// This modifier creates a ``Text`` view on your behalf, and treats the
    /// localized key similar to ``Text/init(_:tableName:bundle:comment:)``. For
    /// more information about localizing strings, see ``Text``. The
    /// following example shows a tab that has a "New Alerts" badge
    /// when there are new alerts.
    ///
    ///     var body: some View {
    ///         TabView {
    ///             Tab("Home", systemImage: "house") {
    ///                 HomeView()
    ///             }
    ///             Tab("Alerts", systemImage: "bell") {
    ///                 AlertsView()
    ///             }
    ///             .badge(alertsManager.hasAlerts ? "New Alerts" : nil)
    ///         }
    ///     }
    ///
    /// - Parameter key: A string key to display as a badge.
    nonisolated public func badge(_ key: LocalizedStringKey) -> some TabContent<Self.TabValue>

Here it looks like that the signature of .badge has changed to a non-nil LocalizedStringKey from pre-iOS 18 LocalizedStringKey?.

Any ideas how to solve this?