How to get userInfo when user click in notification when app is closed?

From iOS 10 onwards, the method you mention should be called whether app is opening from background or inactive state. Perhaps you are not accessing the userInfo correctly. The example below works for me.

func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {

    let userInfo = response.notification.request.content.userInfo
    if let yourData = userInfo["yourKey"] as? String {
        // Handle your data here, pass it to a view controller etc.
    }
}

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Edit: as per the edit to the question, the notification centre delegate must be set in the didFinishLaunching() method, or the method above will not get called.

UNUserNotificationCenter.current().delegate = self