title: Cannot get response from express endpoint
body: <p>I'm building an API that I intend to use with my react native application. The problem which I'm facing right now is that I when I try to hit this particular route <code>/api/auth/signup</code> in <code>Postman</code> I get the <strong>Could not get any response</strong> error message.</p>
  
  <p>This is the route:</p>
  
  <pre class="lang-js prettyprint-override"><code>//create user token
  router.post(
    "/signup",
    [check("username").isEmail(), check("password").isLength({ min: 6 })],
    async (req, res) =&gt; {
      //validate input field on the backend
      const errors = validationResult(req);
      if (!errors.isEmpty()) {
        return res.status(422).json({ errors: errors.array() });
      }
  
      const { username, password, firstName, lastName } = req.body;
  
      try {
        //search DB if there is an existing user
        let user = await User.findOne({ username });
  
        if (user) {
          return res.status(400).json({ msg: "User already exists" });
        }
  
        const salt = await bcrypt.genSalt(10);
  
        res.status(200).json({ data: salt });
      } catch (error) {}
    }
  );
  
  module.exports = router;
  </code></pre>
  
  <p>The strange thing is that if I remove the <code>User.findOne</code> function I get a response. I don't know why this keeps happening, as I had built a similar application following the same pattern without a problem. </p>
  
  <p>NOTE: In the main app.js I have the <code>app.use(express.json({extended:true})</code>, I've also successfully linked the routes in the main file too. Any help would be greatly appreciated!</p>