.Net Microsoft team Meeting应用编程接口生成访问被拒绝令牌

using Microsoft.Identity.Client;
using System.Net.Http.Headers;
using System.Threading.Tasks;

public class TokenProvider
{
    private const string TenantId = "your-tenant-id";
    private const string ClientId = "your-client-id";
    private const string ClientSecret = "your-client-secret";
    private const string Resource = "https://graph.microsoft.com";

    public static async Task<string> GetAccessTokenAsync()
    {
        IConfidentialClientApplication app = ConfidentialClientApplicationBuilder.Create(ClientId)
            .WithClientSecret(ClientSecret)
            .WithAuthority(new Uri($"https://login.microsoftonline.com/{TenantId}"))
            .Build();

        string[] scopes = new string[] { $"{Resource}/.default" };
        var result = await app.AcquireTokenForClient(scopes).ExecuteAsync();
        return result.AccessToken;
    }
}

using System.Net.Http;
using System.Threading.Tasks;

public class TeamsMeetingService
{
    private readonly HttpClient _httpClient;

    public TeamsMeetingService(HttpClient httpClient)
    {
        _httpClient = httpClient;
    }

    public async Task<string> CreateMeetingAsync(string accessToken)
    {
        _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
        var response = await _httpClient.PostAsJsonAsync("https://graph.microsoft.com/v1.0/me/onlineMeetings", new { /* meeting details */ });
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadAsStringAsync();
    }
}