Vercel / Next .js no longer publish an example custom webserver for Next.js 14 App router.

There is a discussion here https://github.com/vercel/next.js/discussions/49326 - and a few 'hidden' Medium posts, but none that show a clear Express / Next.js 14 App router configuration. 

As with Next 13 and the Pages example that Vercel have published, if you create a custom server you will not be able to deploy to Vercel.