I use npm run build to build a next project. I get .next folder, but server.js and web.config – even if they are in project folderm are not added to the build folder. I copy these two files manually – without them I jst get a list of files in build folder when I deploy my build folder – . I also make sure that the iis has read/execute / read / and other acesses to build folder. Here are server.js and web.config that I add manually:

const { createServer } = require('http')
const { parse } = require('url')
const next = require('next')
 
const dev = process.env.NODE_ENV !== 'production'
const port = process.env.PORT || 3000
const hostname = 'localhost'
// when using middleware `hostname` and `port` must be provided below
const app = next({ dev, hostname, port })
const handle = app.getRequestHandler()
 
app.prepare().then(() => {
  createServer(async (req, res) => {
    try {
      // Be sure to pass `true` as the second argument to `url.parse`.
      // This tells it to parse the query portion of the URL.
      const parsedUrl = parse(req.url, true)
      const { pathname, query } = parsedUrl
 
      if (pathname === '/a') {
        await app.render(req, res, '/a', query)
      } else if (pathname === '/b') {
        await app.render(req, res, '/b', query)
      } else {
        await handle(req, res, parsedUrl)
      }
    } catch (err) {
      console.error('Error occurred handling', req.url, err)
      res.statusCode = 500
      res.end('internal server error')
    }
  })
    .once('error', (err) => {
      console.error(err)
      process.exit(1)
    })
    .listen(port, () => {
      console.log(`> Ready on http://${hostname}:${port}`)
    })
})

   <configuration>
  <system.webServer>
    <!-- Visit http://blogs.msdn.com/b/windowsazure/archive/2013/11/14/introduction-to-websockets-on-windows-azure-web-     sites.aspx for more information on WebSocket support -->
    <webSocket enabled="false" />
    <handlers>
      <!-- Indicates that the server.js file is a node.js site to be handled by the iisnode module -->
      <add name="iisnode" path="server.js" verb="*" modules="iisnode"/>
    </handlers>
    <rewrite>
      <rules>
        <!-- Do not interfere with requests for node-inspector debugging -->
        <rule name="NodeInspector" patternSyntax="ECMAScript" stopProcessing="true">
          <match url="^server.js/debug[/]?" />
        </rule>

        <!-- First we consider whether the incoming URL matches a physical file in the /public folder -->
        <rule name="StaticContent">
          <action type="Rewrite" url="public{REQUEST_URI}"/>
        </rule>

        <!-- All other URLs are mapped to the node.js site entry point -->
        <rule name="DynamicContent">
          <conditions>
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="True"/>
          </conditions>
          <action type="Rewrite" url="server.js"/>
        </rule>
      </rules>
    </rewrite>
    
    <!-- 'bin' directory has no special meaning in node.js and apps can be placed in it -->
    <security>
      <requestFiltering>
        <hiddenSegments>
          <add segment="node_modules"/>
        </hiddenSegments>
      </requestFiltering>
    </security>

    <!-- Make sure error responses are left untouched -->
    <httpErrors existingResponse="PassThrough" />
    <iisnode node_env="production" />

    <!--
      You can control how Node is hosted within IIS using the following options:
        * watchedFiles: semi-colon separated list of files that will be watched for changes to restart the server
        * node_env: will be propagated to node as NODE_ENV environment variable
        * debuggingEnabled - controls whether the built-in debugger is enabled

      See https://github.com/tjanczuk/iisnode/blob/master/src/samples/configuration/web.config for a full list of options
    -->
    <!--<iisnode watchedFiles="web.config;*.js"/>-->
  </system.webServer>
   </configuration>

But now when I click on browse in IIS I get this error message saying:

Application has thrown an uncaught exception and is terminated:
Error: Cannot find module ‘next’
Require stack:

• C:WebSites.nextserver.js
• C:Program Filesiisnodeinterceptor.js

any idea?

I also looked at all these theards:

NextJS cannot find a valid build in the ‘.next’ directory

Deploying NextJS app on IIS web server not working

Does Next js production build need node_modules folder in the server?

iisnode encountered an error when processing the request

But none of them really address my issue.