我的应用程序在本地主机上运行得非常好，但一旦我部署到Heroku，我就遇到了以下错误：

当我在客户端使用console.log(response.data)时，我收到了这个字符串，而不是带有我的用户信息的res.json:

"

app.use(
  cors({
    headers: {
      "Content-Type": "application/json",
      "Access-Control-Allow-Origin": "*",
    },
    credentials: true,
    origin: ["https://climber-nation.herokuapp.com/"],
    methods: ["GET", "POST"],
  })
);

//VALIDATE AUTHENTICATION TOKEN
const authenticateToken = (req, res, next) => {
  try {
    const token = req.headers["authorization"];

    if (token == null) {
      return res.sendStatus(401);
    } else {
      jwt.verify(token, process.env.ACCESS_TOKEN_SECRET, (error, decoded) => {
        if (error) {
          return res.sendStatus(403);
        } else {
          req.user = decoded;

          return next();
        }
      });
    }
  } catch (error) {
    console.log(error);
    return res.status(400).json({ error: error });
  }
};

//AUTHENTICATION

app.get("/authentication", authenticateToken, async (req, res) => {
  const username = req.user.username;

  const allUserInfo = await db("users").select("*").where("username", username);

  const image = await db("images")
    .innerJoin("users", "images.image_id", "users.user_id")
    .select("filename")
    .where("username", username);

  const imageFile =
    "https://climber-nation.herokuapp.com/images/" + image[0]?.filename;

  res.json({
    allUserInfo: allUserInfo[0],
    imageFile: imageFile,
  });
});