I am trying to connect to my Raspberry Pi 4 bluetooth from a Flutter app.

However, the flutter app is not even recognizing the Raspberry Pi 4 bluetooth.

This is the app screen which only shows the earphone.
App Interface showing the available bluetooth devices

This is my phone’s bluetooth control screen which shows both the Pi – nil and my local PC.
New Pair Screen

Ans this is my code –

    import 'package:flutter/material.dart';
    import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';
    import 'dart:async';
    
    class ConnectDeviceScreen extends StatefulWidget {
      @override
      _BluetoothModuleState createState() => _BluetoothModuleState();
    }
    
    class _BluetoothModuleState extends State<ConnectDeviceScreen> {
      final FlutterReactiveBle _ble = FlutterReactiveBle();
      List<DiscoveredDevice> _devices = [];
      StreamSubscription<DiscoveredDevice>? _scanSubscription;
      StreamSubscription<ConnectionStateUpdate>? _connectionSubscription;
      bool _isScanning = false;
    
      @override
      void initState() {
        super.initState();
        _checkBleStatus();
      }
    
      void _checkBleStatus() {
        _ble.statusStream.listen((status) {
          print('BLE status: $status');
          if (status == BleStatus.ready) {
            _startScan();
          }
        });
      }
    
      void _startScan() {
        setState(() {
          _isScanning = true;
          _devices.clear();
        });
    
        _scanSubscription = _ble.scanForDevices(
          withServices: [], // Empty list means scan for all devices
          scanMode: ScanMode.lowLatency,
        ).listen(
          (device) {
            setState(() {
              final knownDeviceIndex =
                  _devices.indexWhere((d) => d.id == device.id);
              if (knownDeviceIndex >= 0) {
                _devices[knownDeviceIndex] = device;
              } else {
                _devices.add(device);
              }
            });
          },
          onError: (Object error) {
            print('Scanning failed: $error');
            setState(() {
              _isScanning = false;
            });
          },
        );
    
        // Stop scanning after 10 seconds
        Timer(Duration(seconds: 60), () {
          _stopScan();
        });
      }
    
      void _stopScan() {
        _scanSubscription?.cancel();
        setState(() {
          _isScanning = false;
        });
      }
    
      Future<void> _connectToDevice(DiscoveredDevice device) async {
        try {
          print('Connecting to ${device.name}...');
          _connectionSubscription = _ble
              .connectToDevice(
            id: device.id,
            connectionTimeout: const Duration(seconds: 5),
          )
              .listen(
            (connectionState) {
              print('Connection state: ${connectionState.connectionState}');
              if (connectionState.connectionState ==
                  DeviceConnectionState.connected) {
                print('Connected to ${device.name}');
                // Here you can perform operations like service discovery,
                // reading/writing characteristics, etc.
                // For example:
                // _discoverServices(device.id);
              }
            },
            onError: (Object error) {
              print('Connection failed: $error');
            },
          );
        } catch (e) {
          print('Failed to connect: $e');
        }
      }
    
      // Example of reading a characteristic
      // You'll need to replace the UUIDs with your specific ones
      Future<void> _readCharacteristic(String deviceId) async {
        final characteristic = QualifiedCharacteristic(
          serviceId: Uuid.parse("YOUR_SERVICE_UUID"),
          characteristicId: Uuid.parse("YOUR_CHARACTERISTIC_UUID"),
          deviceId: deviceId,
        );
        try {
          final response = await _ble.readCharacteristic(characteristic);
          print('Read characteristic: ${response}');
        } catch (e) {
          print('Error reading characteristic: $e');
        }
      }
    
      @override
      Widget build(BuildContext context) {
        return Scaffold(
          appBar: AppBar(title: Text('Bluetooth Devices')),
          body: ListView.builder(
            itemCount: _devices.length,
            itemBuilder: (context, index) {
              return ListTile(
                title: Text(_devices[index].name),
                subtitle: Text(_devices[index].id),
                trailing: ElevatedButton(
                  child: Text('Connect'),
                  onPressed: () => _connectToDevice(_devices[index]),
                ),
              );
            },
          ),
          floatingActionButton: FloatingActionButton(
            onPressed: _isScanning ? _stopScan : _startScan,
            child: Icon(_isScanning ? Icons.stop : Icons.search),
          ),
        );
      }
    
      @override
      void dispose() {
        _scanSubscription?.cancel();
        _connectionSubscription?.cancel();
        super.dispose();
      }
    }

Why can’t the flutter app recognize the Raspberry Pi ? When I am connecting normally, using the default phone pairing method outside the flutter app, it connects fine with Pi.