使用Aws Cognito身份池进行Facebook身份验证的错误

Question

我们使用Aws Cognito身份池将Facebook身份验证添加到了我们的移动应用程序中。当我们尝试在aws服务器上登录并发送测试用户的令牌时，会遇到问题（请参见屏幕截图）。我们该如何解决？

private void FacebookLogin()
{
    AWSConfigs.LoggingConfig.LogTo = LoggingOptions.UnityLogger;
    credentials = new CognitoAWSCredentials("Our Identity pool ID",
        RegionEndpoint.EUCentral1);
    syncManager = new CognitoSyncManager(credentials, RegionEndpoint.EUCentral1);
    playerInfo = syncManager.OpenOrCreateDataset("playerInfo");
    AccessToken token = AccessToken.CurrentAccessToken;

    credentials.AddLogin("graph.facebook.com",token.TokenString);
    playerInfo.Put("name","dasda");
    Synchronize();

}

public void Synchronize()
{
    playerInfo.SynchronizeOnConnectivity();
}