let router = require('koa-router')();
let c2 = require('koa2-connect');
let proxy = require('http-proxy-middleware')
module.exports = router;

//個人頁
router.get('/api/*', c2k(proxy({
  target: "http://localhost:3000",
  changeOrigin:true,
  pathRewrite:{
    '^/api/*':'^/internal/*'
  },
  logLevel: 'debug'
})));

以上為代碼，但是運行時一直報錯

Cannot read property 'on' of undefined TypeError: Cannot read property 'on' of undefined
    at makeInjectedResponse 
    UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 2): Error: Can't set headers after they are sent.
  ``