I try get realtime data using https api but now i move on to websocket.

and it’s my https api using code look like:

class UpstoxService {
  final String accessToken = "token";
  final JsonService jsonService;

  UpstoxService(this.jsonService);


    Future<String?> getInstrumentKey(String tradingSymbol) async {
    try {
      final List<dynamic> data = await jsonService.loadJsonData();
      for (var item in data) {
        if (item['trading_symbol'] == tradingSymbol) {
          return item['instrument_key'];
        }
      }
      return 'null'; // Return null if no match is found
    } catch (e) {
      print("Error finding instrument key: $e");
      return 'null';
    }
  }


  Future<Map<String, String>> fetchStockData(String instrumentKey,String symbol) async {
    final url = Uri.parse('https://api.upstox.com/v2/market-quote/quotes?instrument_key=$instrumentKey');
    final headers = {
      'Accept': 'application/json',
      'Authorization': 'Bearer $accessToken',
    };

    final response = await http.get(url, headers: headers);
    // print(response.statusCode);
    // print("${response.statusCode}");
    if (response.statusCode == 200) {
      var data = jsonDecode(response.body);
      Map<String,String> extractData =  formatData(data['data']["NSE_EQ:$symbol"]);
      return extractData;
    } else {
      throw Exception('No data available');
    }
  }

  Map<String, String> formatData(var data) {
    double open = data['ohlc']!['open'];
    String close = data['ohlc']!['close'].toString();
    double netChange = data['net_change'];
    String percentageChange = ((netChange/open)*100).toStringAsFixed(2);

    return  {
      "currentPrice":close,
      "percentageChange":"$percentageChange%",
      "amountChange":netChange.toString(),
    };
  }
}

But How to get real-time stock data in using WebsocketChannel.

Get real time data using WebSocketChannel for upstox api into the flutter.