I previously deployed the app by running npm run build and copied the .next, public, node_modules and the following server.js to the deploy folder.

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 app = next({ dev });
const handle = app.getRequestHandler();

app.prepare().then(() => {
    createServer((req, res) => {
        const parsedUrl = parse(req.url, true);

        handle(req, res, parsedUrl);
    }).listen(port, (err) => {
        if (err) throw err;
        console.log(`> Ready on http://localhost:${port}`);
    });
});

This worked fine but the deployment folder was almost 400 mb. Then I came across this configuration.

const nextConfig = {
    output: "standalone",
};

Which results in 40 mb. Then I copy the public, .next/static to .next/standalone and use that folder to deploy.

But I get the following error when I try to access the site.

iisnode encountered an error when processing the request.

HRESULT: 0x2
HTTP status: 500
HTTP subStatus: 1001
HTTP reason: Internal Server Error
You are receiving this HTTP 200 response because system.webServer/iisnode/@devErrorsEnabled configuration setting is 'true'.

In addition to the log of stdout and stderr of the node.exe process, consider using debugging and ETW traces to further diagnose the problem.

The last 64k of the output generated by the node.exe process to stderr is shown below:

(node:35548) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.
(Use `node --trace-deprecation ...` to show where the warning was created)

But I can manually start the application by running node server.js.

How to resolve this issue?