如何在pug文件中获取dropdown的值？

select(name='dropdown')
  option(value='option1') Option 1
  option(value='option2') Option 2
  option(value='option3') Option 3

const express = require('express');
const bodyParser = require('body-parser');
const app = express();

app.use(bodyParser.urlencoded({ extended: false }));

app.post('/submit', (req, res) => {
  const dropdownValue = req.body.dropdown;
  // 处理dropdown的值
  res.send(`Dropdown value: ${dropdownValue}`);
});

app.listen(3000, () => {
  console.log('Server started on port 3000');
});

form(action='/submit' method='post')
  select(name='dropdown')
    option(value='option1') Option 1
    option(value='option2') Option 2
    option(value='option3') Option 3
  input(type='submit' value='Submit')