iisnode encountered an error when processing the request.

HRESULT: 0x2
HTTP status: 500
HTTP subStatus: 1002
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:716) [MONGODB DRIVER] Warning: Current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
(Use `node --trace-warnings ...` to show where the warning was created)
(node:716) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.
MongoDB connection error: MongoNetworkError: failed to connect to server [localhost:27017] on first connect [Error: connect ECONNREFUSED ::1:27017
    at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1300:16) {
  name: 'MongoNetworkError'
}]