I am getting the following error when trying to get all documents from a collection in Firestore using firebase admin SDK:

[nuxt] [request error] Expected first argument to collection() to be a CollectionReference, a DocumentReference or FirebaseFirestore

I am testing via a simple console.log:

/server/api/posts.js:

import { firestore } from '../utils/firebase'
import { collection, getDocs } from 'firebase/firestore'

export default defineEventHandler(async (event) => {
  const colRef = collection(firestore, 'posts')
  console.log(colRef)
})

Here is how I am initializing firestore:

/server/utils/firebase.js:

import { initializeApp, cert } from 'firebase-admin/app'
import { getFirestore } from 'firebase-admin/firestore'
import serviceAccount from '../../service-account.json'

export const app = initializeApp({
  credential: cert(serviceAccount)
})

export const firestore = getFirestore()

Note: The following code works on the server-side and I am able to get a document back, but for some reason I can't use the collection() like in the above example.

import { firestore } from '../utils/firebase'

export default defineEventHandler(async (event) => {
  const ref = firestore.doc(`animals/dog`)
  const snapshot = await ref.get()
  const data = snapshot.data()
  console.log(data)
  // return {
    // data
  // }
})

Also, if I run the collection() function on the client side, I can successfully retrieve the posts. I just can't figure out why it won't work server-side.

Anyone know why I get the above error?