Where should I export server code in nextJS in case of code splitting?

Question

In a nextJs project connected to mongoDB, I have multiple database connection in multiple getStaticProps and getStaticPaths functions.

The code works but is repeating multiple times in my project :

const client = await MongoClient.connect('mongodb+srv://xxxxxxxx')
const db = client.db()
const meetupsCollection = db.collection('meetups')
const result = await meetupsCollection.insertOne(something) //or any other db method
client.close()

I would like to refactor this code and just create a helper/dbConnect.js folder with the code bellow, but when I import and deploy mongoConnect() to the rest of the code, it doesn't work.

//  /helper/mongoConnect.js

import {MongoClient} from 'mongodb'
const mongoConnect = async () => {
  const client = await MongoClient.connect('mongodb+srv://xxxxx')
  const db = client.db()
  const meetupsCollection = db.collection('meetups')
  return meetupsCollection
}
export default mongoConnect

// /pages/index.js
import mongoConnect from '../helper/mongoConnect'
 
/* here is my page component*/

export const getStaticProps = async () => {
  const meetupsCollection = await mongoConnect()
  const meetups = await meetupsCollection..insertOne(something) //or any other db method
  client.close()
  return {
     props: {
       ...
     })),
  },
  revalidate: 10,
  }
}

Where should I put this helper file without exposing anything to client? /pages? /api? If I put it in my project root /, I have error messages (dns, net, tls, fs,...) like:

Failed to compile

./node_modules/mongodb/lib/cmap/auth/gssapi.js:4:0
Module not found: Can't resolve 'dns'

https://nextjs.org/docs/messages/module-not-found

Import trace for requested module:
./node_modules/mongodb/lib/index.js
./pages/index.jsx

Thanks in advance