Formidable returns TypeError, ERR_INVALID_ARG_TYPE: The "path" argument is undefined

I'm having trouble uploading files using formidable. I'm on Windows server 2016.

My code, which in its entirely is shown below, is based on https://www.geeksforgeeks.org/how-to-upload-file-using-formidable-module-in-node-js/

const express = require('express');const fs = require('fs');const path = require('path')const formidable = require('formidable');const app = express();app.post('/api/upload', (req, res, next) => {    const form = new formidable.IncomingForm(        { uploadDir: __dirname +'\\tmp',  keepExtensions: true }    );    form.parse(req, function(err, fields, files){        var oldPath = files.profilePic.path;        var newPath = path.join(__dirname, 'uploads')+'/'+files.profilePic.name        var rawData = fs.readFileSync(oldPath)        fs.writeFile(newPath, rawData, function(err){            if(err) console.log(err)            return res.send("Successfully uploaded")        })  })});app.listen(3000, function(err){    if(err) console.log(err)    console.log('Server listening on Port 3000');});

I use Postman to send a file.

When triggering the /api/upload API, the file sent is correctly placed in the tmp folder, but reading the path is when the problem arise:

TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string or an instance of Buffer or URL. Received undefined

This message points to fs.readFileSync(oldPath).

console.log('files='+files) returns files=[object Object]

console.log('files.profilePic='+files.profilePic) returns

C:\somepath\node_modules\formidable\src\PersistentFile.js:50    return `PersistentFile: ${this._file.newFilename}, Original: ${this._file.originalFilename}, Path: ${this._file.filepath}`;                                         ^TypeError: Cannot read properties of undefined (reading 'newFilename')    at PersistentFile.toString (C:\somepath\node_modules\formidable\src\PersistentFile.js:50:42)

All 4 referenced modules exist in node_modules folder.