我无法将频道设为私人

Question

好吧，我这样做的目的是使用户可以创建一个频道，为其命名，定位的类别以及可以加入该频道的角色，但我不知道如何将其设为私有

public IPrivateChannel _privateChannel;

public async  Task PrivateChannels(string name, ulong categorychannel, IRole role) {
    OverwritePermissions permissions = new OverwritePermissions();
    var privateChannel = _privateChannel;
    var voiceChannel =  await Context.Guild.CreateVoiceChannelAsync(name, x => x.CategoryId = categorychannel);
    await voiceChannel.AddPermissionOverwriteAsync(role, permissions);
}