Hey I am trying to deploy a react app with a backend in nodeJS.

here is my directory tree

and here is my vercel.json

    {
  "version": 2,
  "builds": [
    {
      "src": "backend/server/index.js",
      "use": "@vercel/node"
    },
    {
      "src": "client/package.json",
      "use": "@vercel/static-build",
      "config": {
        "distDir": "build"
      }
    }
  ],
  "rewrites": [
    {
      "source": "/api/(.*)",
      "destination": "backend/server"
    },
    {
      "source": "/(.*)",
      "destination": "/client/$1"
    }
  ]
}

The frontend works and I get to interact with the react part but I am unable to access the node server and outputs this error when I try to use it

file:///C:/Users/user/AppData/Roaming/npm/node_modules/vercel/node_modules/@vercel/node/dist/dev-server.mjs:1073
    return listener(req, res);
           ^
file:///C:/Users/user/AppData/Roaming/npm/node_modules/vercel/node_modules/@vercel/node/dist/dev-server.mjs:1073
    return listener(req, res);
           ^
TypeError: listener is not a function
    at Server.<anonymous> (file:///C:/Users/user/AppData/Roaming/npm/node_modules/vercel/node_modules/@vercel/node/dist/dev-server.mjs:1073:12)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
TypeError: listener is not a function
    at Server.<anonymous> (file:///C:/Users/user/AppData/Roaming/npm/node_modules/vercel/node_modules/@vercel/node/dist/dev-server.mjs:1073:12)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
Error: An unexpected error occurred!
Error: Command failed: taskkill /pid 22452 /T /F
ERROR: The process "22452" not found.

    at genericNodeError (node:internal/errors:984:15)
    at wrappedFn (node:internal/errors:538:14)
    at ChildProcess.exithandler (node:child_process:422:12)
    at ChildProcess.emit (node:events:519:28)
    at ChildProcess.emit (node:domain:488:12)
    at maybeClose (node:internal/child_process:1105:16)
    at ChildProcess._handle.onexit (node:internal/child_process:305:5)
Error: An unexpected error occurred!
Error: Command failed: taskkill /pid 16132 /T /F
ERROR: The process "16132" not found.

    at genericNodeError (node:internal/errors:984:15)
    at wrappedFn (node:internal/errors:538:14)
    at ChildProcess.exithandler (node:child_process:422:12)
    at ChildProcess.emit (node:events:519:28)
    at ChildProcess.emit (node:domain:488:12)
    at maybeClose (node:internal/child_process:1105:16)
    at Socket.<anonymous> (node:internal/child_process:457:11)
    at Socket.emit (node:events:519:28)
    at Socket.emit (node:domain:488:12)
    at Pipe.<anonymous> (node:net:339:12)