Chcę uzyskać listę pakietów w prywatnym kanale z uwierzytelnianiem HTTP. To jest mój kod, gdy wywołam metodę ListPlugins Otrzymuję błąd 401, jak mogę ustawić poświadczenia?

public  class PluginManager
{
    private readonly string _pluginFolder;
    private readonly IPackageRepository _packageRepository;
    private readonly PackageManager _packageManager;

    public PluginManager(string plugInFolder, string packageRepositoryAddres)
    {
        _pluginFolder = plugInFolder;
        _packageRepository = PackageRepositoryFactory.Default.CreateRepository(packageRepositoryAddres);
        _packageManager = new PackageManager(_packageRepository, _pluginFolder);  
    }

    public IEnumerable<PluginModel> ListPlugins()
    {
        IPackage dummy = null;

        var result =  _packageManager.SourceRepository.GetPackages()
            .OrderBy(p => p.Id)
            .ToList()
            .Select(p => new PluginModel()
            {
                PackageId = p.Id,
                PackageVersion = p.Version.ToString(),
                PackageDescription = p.Description,
                IsInstalled = _packageManager.LocalRepository.TryFindPackage(p.Id, p.Version, out dummy)
            })
            .ToList();

        return result;
    }

    public void Install(string packageId, string packageVersion)
    {
        _packageManager.InstallPackage(packageId, new SemanticVersion(packageVersion));
    }

    public void Uninstall(string packageId, string packageVersion)
    {
        _packageManager.UninstallPackage(packageId, new SemanticVersion(packageVersion));
    }
}