`SyntaxError：await 仅在异步函数中有效`，同时尝试在 node rest api 中注册用户

router.post("/register", async (req, res) => {
  const firstName = req.body.firstName;
  const lastName = req.body.lastName;
  const email = req.body.email;
  const phone = req.body.phone;
  const gender = req.body.gender;
  const country = req.body.country;
  const password = req.body.passwordHash;

  bcrypt.hash(password, 10, (err, hash) => {
    if (err) {
      console.log("error: " + err);
    } else {
      const newUser = new User({
        firstName,
        lastName,
        email,
        phone,
        gender,
        country,
        passwordHash: hash,
      });
      try {
        const savedUser = await newUser.save()
        res.send(savedUser)
      } catch (err) {
        res.status(400).send(err)
      }
      
    }
  });
});