How can I customize the Android notification on Flutter?

To customize the Android notification display and behavior on Flutter, consider using a package called flutter_local_notifications which allows granular configuration of local Android notifications, instead of calling Pushy.notify(...) in your backgroundNotificationListener().

Example code to display a local notification with flutter_local_notifications:

const AndroidNotificationDetails androidPlatformChannelSpecifics =
    AndroidNotificationDetails(
        'your channel id', 'your channel name', 'your channel description',
        importance: Importance.max,
        priority: Priority.high,
        showWhen: false);
const NotificationDetails platformChannelSpecifics =
    NotificationDetails(android: androidPlatformChannelSpecifics);
await flutterLocalNotificationsPlugin.show(
    0, 'plain title', 'plain body', platformChannelSpecifics,
    payload: 'item x');

Please refer to the docs for configuring custom notification icons and sounds.

To migrate to flutter_local_notifications, remove the following line of code in your backgroundNotificationListener()  and invoke the plugin instead:

Pushy.notify(notificationTitle, notificationText, data);