有没有办法从 twilio 中的语音呼叫中识别字母数字

Question

感谢您的帮助，现在我在语音通话中使用Twilio.alphanumeric自动驾驶机器人... 但我尝试了很多次，但总是出错......我该如何解决这个问题？ 我可以为此使用<Gather hints="letter and number">吗？ 但是如何使用呢？ 现在我正在使用下面的代码......

{
"actions": [
    {
        "say": "I am a robot ..."
    },
    {
        "collect": {
            "name": "vin_code",
            "questions": [
                {
                    "confirm": {
                        "on_confirm": {
                            "say": "perfect, let's continue..."
                        },
                        "max_attempts": {
                            "redirect": "task://fallback",
                            "num_attempts": 5
                        },
                        "messages": [
                            {
                                "say": "I heard code is <prosody rate='30%'><say-as interpret-as='spell-out'>{vin}</say-as></prosody>, right?"
                            },
                            {
                                "say": "Your code is <prosody rate='30%'><say-as interpret-as='spell-out'>{vin}</say-as></prosody>, right?"
                            }
                        ],
                        "on_reject": {
                            "messages": [
                                {
                                    "say": "I'm sorry, let's try again. What is your code number?"
                                },
                                {
                                    "say": "My bad, can you tell me again. what is your code number?"
                                }
                            ]
                        }
                    },
                    "question": "What is your code?",
                    "name": "vin",
                    "type": "Twilio.ALPHANUMERIC"
                }
            ],
            "on_complete": {
                "redirect": {
                    "method": "POST",
                    "uri": "https://"fucntion url.twil.io/...
                }
            }
        }
    }
]

}