How can I check if my SwiftUI application is in the background from a NotificationService Extension?

Question

I am using a notification service extension in my app to handle push notifications when the app is in the background:

override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {
    self.contentHandler = contentHandler
    bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)
    if let bestAttemptContent = bestAttemptContent {
        if let userInfo = request.content.userInfo as? [String: AnyObject] {
            
            if UIApplication.shared.applicationState == .background { // error 'shared' is unavailable in application extensions for iOS: Use view controller based solutions where appropriate
                
            }
            
            PushNotificationHelper.handleNotification(userInfo: userInfo, context: persistentContainer.viewContext)
            contentHandler(bestAttemptContent)
        } else {
            contentHandler(bestAttemptContent)
        }
    }
}

However, I notice this is also being called when the app is in the foreground which I don't want.

I wanted to return from this function without doing anything when app is in foreground but when I try 'if UIApplication.shared.applicationState == .background' I get the error message included above.

How can I check the application state from this extension?