code: public static Single<String> sendVoice(String apikey, String mobile, String code) {
          Map<String, String> params = new HashMap<>();
          params.put("apikey", apikey);
          params.put("mobile", mobile);
          params.put("code", code);
          return post(URI_SEND_VOICE, params);
      }
docs: 通过接口发送语音验证码
  
  @param apikey apikey
  @param mobile 接收的手机号
  @param code   验证码
  @return the http result