I'm having issue with teledart.onMessage(entityType: '*').listen((message) is not executing when running as Release and the app is in Background state for iOS

[sotheavuthnguon]

Describe the bug

• I enable the capabilities Background fetch and Background processing in Xcode:

• Click on "Join Telegram" button to add the telegram bot to the telegram group and start listening to the onMessage method

  
  ElevatedButton(
            onPressed: () async {
              const token = "BOT_TOKEN";
              final username = (await Telegram(token).getMe()).username!;
              final teledart = TeleDart(token, Event(username));
              teledart.start();
              teledartStartListening(teledart);
              String url =
                  "https://t.me/$username?startgroup=$username&admin=manage_chat,change_info,delete_messages,restrict_members,invite_users,pin_messages,manage_video_chats";
              await launchUrl(Uri.parse(url), mode: LaunchMode.platformDefault);
            },
            child: const Text("Join Telegram"),
          )

void teledartStartListening(TeleDart teledart) async { teledart.onMessage(entityType: '*').listen((message) async { debugPrint('Received message => ${message.text}'); final textMessage = message.text; if (textMessage?.compareTo("111111") == 0) { teledart.stop();

  message.reply("Congratulations", parseMode: "HTML");
  // After verify OTP on telegram success we need to call to make update to back-end server.
} else {
  if (textMessage == "" &&
      message.from != null &&
      message.from?.isBot == true &&
      (message.chat.type.toUpperCase() == "group".toUpperCase() ||
          message.chat.type.toUpperCase() == "supergroup".toUpperCase())) {
    message.reply("Hello", parseMode: "HTML");
  } else {
    message.reply("Hello", parseMode: "HTML");
  }
}

}); }

I cannot receive the messages when running as **Release** and the app is in **Background** state, but when running as Debug, I can receive the messages as normal.

## Expected behavior
I would like the behavior that we can still receiving messages in Telegram when running as **Release** and the app is in **Background** state. Thanks.

[DinoLeung]

Not a iOS expert here, would be good if someone can contribute to this issue. My understanding is that the teledart stuff need to be run in the background thread, so the instance will not be destroy once the on pressed event is finished.