[2664] nuxt express post conflict?

i use https://github.com/nuxt-community/express-template

but i don't know why Build only in dev mode?

// Build only in dev mode
if (config.dev) {
  const builder = new Builder(nuxt)
  builder.build()
}

in here define a post router like this https://github.com/nuxt-community/express-template/blob/master/template/server/api/users.js

import { Router } from 'express'

const router = Router()

router.post('/doc_enter', function(req, res, next) {
  if (req.body.pw) {
    return res.json({success:req.body.pw})
  }
})

but req.body is undefined

i use bodyParser at https://github.com/nuxt-community/express-template/blob/master/template/server/index.js

const bodyParser = require('body-parser')

app.use(bodyParser.json({limit:'900kb'}))

app.use('/api', api)
const nuxt = new Nuxt(config)

// Build only in dev mode
if (config.dev) {
  const builder = new Builder(nuxt)
  builder.build().catch((error) => {
    console.error(error)
    process.exit(1)
  })
}

app.use(nuxt.render)

now the req.body has value .but other proxy PHP API timeout which has post data

superagent
  .post('/api/user/login')
  .send({ ip, ...form }) // sends a JSON post body
  .set('accept', 'json')
  .end((err, res) => {
    // Calling the end function will send the request
  })

The request headers Provisional headers are shown

What should i do if i wanna keep the proxy PHP API and express middleware api all be right?