Not able to use Binance_spot Package in Flutter Dart - flutter

Question

I am trying for the past two days to Get user data from binance Api with the Binance test net key using package https://pub.dev/packages/binance_spot/example
I tried every way possible I learned as I am a beginner I am not able to get the user data from the user account
I also changed the links that work for the testnet finance API version
here is the example code snippet
import 'dart:async';
import 'package:binance_spot/binance_spot.dart';
import 'package:flutter/material.dart' hide Interval;
class BinanceScreen extends StatefulWidget {
const BinanceScreen({Key? key}) : super(key: key);
#override
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<BinanceScreen> {
BinanceSpot binanceSpot = BinanceSpot(
key: "3HKUUgtwu8WFWh4q31C5bh1veQqMEkEbF07hpMrq8xnwYsWDnj0ZWgYQkvC3gnE0",
secret: "KWwvWOi4nu8s0Qsi87iJ523cfp9Jcl8mFwt2hZHptMyahhGsxnmvdURIxVa9zA74",
);
double lastClosePrice = 0;
String tradablePairs = "";
String lastEventData = "";
WsAccountUpdate? balance;
late StreamSubscription<dynamic> klineStreamSub;
late StreamSubscription<dynamic> userdataStreamSub;
#override
void initState() {
startKlineStream();
startUserdataStream();
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text("Binance API tester"),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text("Current BTC price : $lastEventData"),
// Text("Last userdataStream event : ${balance}"),
TextButton(
onPressed: getTradablePairs,
child: const Text("GET PAIRS"),
),
Expanded(
flex: 1,
child: SelectableText(
tradablePairs,
maxLines: 200,
minLines: 1,
),
),
],
),
),
);
}
void startKlineStream() {
var stream = binanceSpot.klineStream(
symbol: "BTCUSDT",
interval: Interval.INTERVAL_5m,
);
klineStreamSub = stream.listen(handleNewKline);
}
void handleNewKline(WsKlineEvent event) {
setState(() {
lastClosePrice = event.kline.close;
});
}
void startUserdataStream() async {
var response = await binanceSpot.createListenKey();
if (response.isRight) {
var stream = binanceSpot.userDataStream(listenKey: response.right);
userdataStreamSub = stream.listen(handleUserdataEvent);
} else {
lastEventData = response.left;
}
}
void handleUserdataEvent(dynamic event) {
if (event is WsAccountUpdate) {
lastEventData =
"Account update event : ${event.balances.length} balances updated";
} else if (event is WsBalanceUpdate) {
lastEventData = "Balance update event : ${event.asset} balance updated";
} else if (event is WsExecutionReport) {
lastEventData =
"Execution report event : status is ${event.orderStatus.toStr()}";
} else if (event is WsListOrderStatus) {
lastEventData =
"ListOrder update event : status is ${event.listOrderStatus}";
} else {
lastEventData = "Unknown event type : ${event.toString()}";
}
}
void getTradablePairs() async {
var response = await binanceSpot.exchangeInfo();
if (response.isLeft) {
tradablePairs = response.left;
} else {
var listSymbol = response.right.symbols.map((e) => e.symbol).toList();
tradablePairs = "";
for (var s in listSymbol) {
tradablePairs += "$s ";
}
}
}
#override
void dispose() {
klineStreamSub.cancel();
userdataStreamSub.cancel();
super.dispose();
}
}
and here is the class code snippet which I want to acess
class WsOcoOrder {
String symbol;
int orderId;
String clientOrderId;
WsOcoOrder.fromMap(Map m)
: symbol = m['s'],
orderId = m['i'],
clientOrderId = m['c'];
}
What is the Possible way to access this class and its data in the above-given code snippet
Please refer me to the solution or a Link from where I can learn and implement by myself