How to integrate push notification using one signal in flutter

onesignal.dart

## step 1 - add intent in AndroidManifest.xml file

            <intent-filter>
                <action android:name="FLUTTER_NOTIFICATION_CLICK" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>

## step 2 - add this in main.dart file in main function

  WidgetsFlutterBinding.ensureInitialized();
  await OneSignal.shared.setAppId(appid);
  OneSignal.shared.setNotificationWillShowInForegroundHandler(
    (OSNotificationReceivedEvent event) {
      // Will be called whenever a notification is received in foreground
      // Display Notification, pass null param for not displaying the notification
      Logger().w(event.notification);
      Logger().e(event.notification.rawPayload);
      event.complete(event.notification);
    },
  );
 
## step 3 - add this in dashboard.dart file in initstate function 


    OneSignal.shared.setNotificationOpenedHandler(
      (OSNotificationOpenedResult result) {
        // Will be called whenever a notification is opened/button pressed.

        Logger().w(result.notification.additionalData);
        String path = result.notification.additionalData!['key1'];
        Logger().e(path);
        Get.toNamed(
          '/$path',
        );
      },
    );