如何解决Twilio的"Invalid messaging binding address"错误？

我按照Twilio的对话参与者资源教程操作，尝试给对话添加参与者时遇到报错。网上能找到的相关错误文档只提示要确保电话号码格式有效，但我检查后还是收到以下错误：

Twilio.Exceptions.ApiException: Invalid messaging binding address
at Twilio.Clients.TwilioRestClient.ProcessResponse(Response response)
at Twilio.Clients.TwilioRestClient.Request(Request request)
at Twilio.Rest.Conversations.V1.Conversation.ParticipantResource.Create(CreateParticipantOptions options, ITwilioRestClient client)

我的代码如下：

TwilioClient.Init(_appSettingService.TWilioAccountSid, _appSettingService.TwilioAuthToken);

var participant = ParticipantResource.Create(
      messagingBindingAddress: "+14704318899",
      messagingBindingProxyAddress: _appSettingService.TwilioPhoneNumber,
      pathConversationSid: "CHec09eb5ef6474f25b6e8dd0ea79affb6"
);

内容的提问来源于stack exchange，提问作者levj1