我在MERN堆栈代码文件中有这个，它工作得很好。

exports.chatbot = async (req, res) => {
  console.log("OpenAI Chatbot Post");

  const { textInput } = req.body;

  try {

    const response = await openai.createCompletion({
      model: "text-davinci-003",
      prompt: `
            What is your name?
            My name is Chatbot.
            How old are you?
            I am 900 years old.
            ${textInput}`,
      max_tokens: 100,
      temperature: 0,
    });
    if (response.data) {
      if (response.data.choices[0].text) {
        return res.status(200).json(response.data.choices[0].text);
      }
    }
  } catch (err) {
    return res.status(404).json({ message: err.message });
  }
};

虽然我改变了API请求，使用新的API聊天完成，这一个不工作（API代码是从openAI网站，和工程 Postman ）

exports.chatbot = async (req, res) => {
  console.log("OpenAI Chatbot Post");

  const { textInput } = req.body;

  try {
    const completion = await openai.createChatCompletion({
      model: "gpt-3.5-turbo",
      messages: [{ role: "user", content: textInput }],
    });
    console.log(completion.data.choices[0].message);

    if (completion.data) {
      if (completion.data.choices[0].message) {
        return res.status(200).json(completion.data.choices[0].message);
      }
    }

  } catch (err) {
    return res.status(404).json({ message: err.message });
  }
};

错误消息：
404（页面未找到）