HTML Subscribe передает undefined данные

При отправке данных из html формы прилетает ошибка: Error: Illegal arguments: undefined, number

Моя HTML форма:

<div class="subscribe-container">
  <form action="/register" method="post">
    <input type="text" name="first_name" placeholder="First Name" required>
    <input type="text" name="last_name" placeholder="Last Name" required>

    <input type="email" name="email" placeholder="Email Address" required>
    <input type="password" name="password" required>

    <input class="subscribe-button" type="submit" value="Subscribe" id="thing">
  </form>

Обрабатывающий app.js:

app.get("/register", async (req, res) => {
       app.get(bodyParser.urlencoded({ extended: true }))
       await res.sendFile(__dirname + "/views/reg.html")    
})

// Register
app.post("/register", async (req, res) => {

    try {
      // Get user input
      const { first_name, last_name, email, password } = req.body;
  
      // Validate user input
      if (!(email && password && first_name && last_name)) {
        res.status(400).send("All input is required");
      }