below is my code I am trying to take an audio input and sending it to gemini api which would scan the audio and tell me its tags and genre I need a solution with getting error in uri

import 'dart:convert';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:file_picker/file_picker.dart';
import 'package:http/http.dart' as http;
import 'package:google_generative_ai/google_generative_ai.dart';

void main() {
  runApp(MusicAnalyzerApp());
}

class MusicAnalyzerApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Gemini Music Analyzer',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MusicAnalyzerHome(),
    );
  }
}

class MusicAnalyzerHome extends StatefulWidget {
  @override
  _MusicAnalyzerHomeState createState() => _MusicAnalyzerHomeState();
}

class _MusicAnalyzerHomeState extends State<MusicAnalyzerHome> {
  String? _filePath;
  String? _musicAnalysis;
  bool _isLoading = false;

  Future<void> _pickFile() async {
    FilePickerResult? result = await FilePicker.platform.pickFiles(type: FileType.audio);

    if (result != null) {
      setState(() {
        _filePath = result.files.single.path;
      });
    } else {
      // User canceled the picker
    }
  }

  Future<void> _analyzeMusic() async {
    if (_filePath == null) return;

    setState(() {
      _isLoading = true;
      _musicAnalysis = null;
    });

    final apiKey = 'apikey';

    final fileId = await uploadFileToGemini(apiKey, _filePath!);
    if (fileId == null) {
      setState(() {
        _isLoading = false;
      });
      _showErrorDialog('File upload failed');
      return;
    }

    final response = await analyzeMusicWithGemini(apiKey, fileId);

    setState(() {
      _isLoading = false;
      _musicAnalysis = response;
    });
  }

  Future<String?> uploadFileToGemini(String apiKey, String filePath) async {
    final uri = Uri.parse('https://generativelanguage.googleapis.com/v1beta/models/gemini-1.5-pro:generateContent?key=apikey'); // Replace with actual upload endpoint

    final request = http.MultipartRequest('POST', uri)
      ..headers['Authorization'] = 'Bearer $apiKey'
      ..files.add(await http.MultipartFile.fromPath('file', filePath));

    final response = await request.send();

    if (response.statusCode == 200) {
      final responseBody = await response.stream.bytesToString();
      final jsonResponse = jsonDecode(responseBody);
      return jsonResponse['fileId']; // Adjust based on the actual response structure
    } else {
      return null;
    }
  }

  Future<String?> analyzeMusicWithGemini(String apiKey, String fileId) async {
    final model = GenerativeModel(
      model: 'gemini-1.5-pro',
      apiKey: apiKey,
      generationConfig: GenerationConfig(
        temperature: 1,
        topK: 64,
        topP: 0.95,
        maxOutputTokens: 8192,
        responseMimeType: 'text/plain',
      ),
    );

    final chat = model.startChat(history: [
      Content.multi([
        FilePart(uri: fileId), // **Here I am getting error with uri undefined**
        TextPart('answer two questions 1 - what kind of music genre and tag it showsn2 - what kind of image genre and tag it shows'),
      ]),
    ]);

    final response = await chat.sendMessage(Content.text('Analyze the music and image tags'));
    return response.text;
  }

  void _showErrorDialog(String message) {
    showDialog<void>(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: const Text('Error'),
          content: Text(message),
          actions: <Widget>[
            TextButton(
              child: const Text('OK'),
              onPressed: () {
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Gemini Music Analyzer'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          children: <Widget>[
            ElevatedButton(
              onPressed: _pickFile,
              child: const Text('Pick an MP3 File'),
            ),
            const SizedBox(height: 16),
            if (_filePath != null)
              Text('Selected file: ${_filePath!.split('/').last}'),
            const SizedBox(height: 16),
            ElevatedButton(
              onPressed: _analyzeMusic,
              child: const Text('Analyze Music'),
            ),
            const SizedBox(height: 16),
            if (_isLoading)
              const CircularProgressIndicator(),
            if (_musicAnalysis != null)
              Expanded(
                child: SingleChildScrollView(
                  child: Text(_musicAnalysis!),
                ),
              ),
          ],
        ),
      ),
    );
  }
}

I tried everything I can and was expecting not to get an error I was thinking that it would be model name but dont know if its correct