要在安卓屏幕上显示通知LED，你可以使用以下步骤和代码示例：

1. 在你的AndroidManifest.xml文件中添加以下权限：

2. 在你的Activity中，添加以下代码来检查并请求通知权限：

private static final int REQUEST_NOTIFICATION_PERMISSION = 123;

private void checkNotificationPermission() {
    NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    if (notificationManager != null && !notificationManager.isNotificationPolicyAccessGranted()) {
        Intent intent = new Intent(android.provider.Settings.ACTION_NOTIFICATION_POLICY_ACCESS_SETTINGS);
        startActivityForResult(intent, REQUEST_NOTIFICATION_PERMISSION);
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == REQUEST_NOTIFICATION_PERMISSION) {
        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        if (notificationManager != null && notificationManager.isNotificationPolicyAccessGranted()) {
            // 权限已授予，可以显示通知LED
            enableNotificationLed();
        }
    }
}

3. 在你的Activity中，添加以下代码来启用通知LED：

private void enableNotificationLed() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        String channelId = "your_channel_id";
        String channelName = "Your Channel Name";
        int importance = NotificationManager.IMPORTANCE_DEFAULT;
        NotificationChannel notificationChannel = new NotificationChannel(channelId, channelName, importance);
        notificationChannel.enableLights(true);
        notificationChannel.setLightColor(Color.RED);
        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        if (notificationManager != null) {
            notificationManager.createNotificationChannel(notificationChannel);
        }
    }
}

4. 在你的代码中，创建一个通知并将通知发送到通知栏。确保设置了正确的通道ID：

private void showNotification() {
    String channelId = "your_channel_id";
    NotificationCompat.Builder builder = new NotificationCompat.Builder(this, channelId)
            .setSmallIcon(R.drawable.your_notification_icon)
            .setContentTitle("Notification Title")
            .setContentText("Notification Text")
            .setPriority(NotificationCompat.PRIORITY_DEFAULT);

    NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
    notificationManager.notify(notificationId, builder.build());
}

以上步骤和代码示例将帮助你在安卓屏幕上显示通知LED。