Setup/Acess Firestore on External Server (Python)

pip install flaskpip install firebase-admin

from flask import Flask, jsonify, abortimport firebase_adminfrom firebase_admin import credentialsfrom firebase_admin import firestoreapp = Flask(__name__)cred = credentials.Certificate('keys/firebase-adminsdk.json')default_app = firebase_admin.initialize_app(cred, {  'projectId': 'nuanxindan',})db = firestore.client()@app.route('/test_firestore')def test_firestore():    doc_ref = db.collection('COLLECTION').document('DOCUMENT_ID')    doc = doc_ref.get()    if doc.exists:        return jsonify(doc.to_dict())    else:        doc_ref.set({'name': 'Hello'})        return 'UPDATED'

pip install google-cloud-firestore

from flask import jsonifyfrom google.cloud import firestoredb = firestore.Client.from_service_account_json('PROJECT_ID-firestore.json')# db = firestore.Client()@app.route('/test_firestore')def test_firestore():    doc_ref = db.collection('test').document('xxx')    doc = doc_ref.get()    if doc.exists:        return jsonify(doc.to_dict())    else:        doc_ref.set({'name': 'Hello'})        return 'UPDATED'