我正在我的Ruby应用程序中设置Agora's authentication workflow，但是当我在Agora Web Demo上测试时，我生成的所有令牌都给予AgoraRTCError CAN_NOT_GET_GATEWAY_SERVER: flag: 4096。
来自Web控制台的完整错误是：

Agora-SDK [ERROR]: [client-48eb2] join number: 1, Joining channel failed, rollback AgoraRTCException: AgoraRTCError CAN_NOT_GET_GATEWAY_SERVER: flag: 4096, message: AgoraRTCError CAN_NOT_GET_GATEWAY_SERVER: invalid token, authorized failed

我使用AgoraDynamicKey2::RtcTokenBuilder从AgoraIO/Tools Github Repo我使用的具体文件是RTC Token Builder
我实现的代码是：

require 'agora_dynamic_key2'
# app/models/chat/participant.rb
# Chat::Participant Model
# This is the model which connects users to chats.
class Chat::Participant < ApplicationRecord

  def agora_token
    app_id = Rails.application.credentials.dig(:agora, :app_id)
    app_certificate = Rails.application.credentials.dig(:agora, :app_certificate)
    channel_name = chat.id
    account = user.id
    token_expiration_in_seconds = 3600
    privilege_expiration_in_seconds = 3600

    AgoraDynamicKey2::RtcTokenBuilder.build_token_with_user_account(
      app_id, app_certificate, channel_name, account,
      AgoraDynamicKey2::RtcTokenBuilder::ROLE_PUBLISHER, token_expiration_in_seconds, privilege_expiration_in_seconds
    )
  end

end

chat.id和user.id都是UUID字符串。
RTC令牌代码来自Agora库：

def self.build_token_with_user_account(app_id, app_certificate, channel_name, account, role, token_expire, privilege_expire = 0)
      access_token = AgoraDynamicKey2::AccessToken.new(app_id, app_certificate, token_expire)
      service_rtc = AgoraDynamicKey2::ServiceRtc.new(channel_name, account)

      service_rtc.add_privilege(AgoraDynamicKey2::ServiceRtc::PRIVILEGE_JOIN_CHANNEL, privilege_expire)
      if role == ROLE_PUBLISHER
        service_rtc.add_privilege(AgoraDynamicKey2::ServiceRtc::PRIVILEGE_PUBLISH_AUDIO_STREAM, privilege_expire)
        service_rtc.add_privilege(AgoraDynamicKey2::ServiceRtc::PRIVILEGE_PUBLISH_VIDEO_STREAM, privilege_expire)
        service_rtc.add_privilege(AgoraDynamicKey2::ServiceRtc::PRIVILEGE_PUBLISH_DATA_STREAM, privilege_expire)
      end
      access_token.add_service(service_rtc)
      access_token.build
    end

我有做错什么吗？有没有人知道一种更好的方法来检查令牌的有效性，并提供更好的错误消息？