Google Credential API one tab sign-in support only google app engine?

Question

I'm learning google one tab sign-in according by https://codelabs.developers.google.com/codelabs/credential-management-api/index.html?index=..%2F..index#1

https://developers.google.com/identity/one-tap/web/guides/get-google-api-clientid

and

https://developers.google.com/web/fundamentals/security/credential-management

with 'password' login it work like a charm (without using python script)

but 'federated' login like google or facebook I have stuck on it.

I see demo server side scripts (main.py) from this repo https://github.com/GoogleChromeLabs/credential-management-sample

from google.appengine.ext import vendor
vendor.add('lib')

import os
import sys
import binascii
import json
import urllib
from bcrypt import bcrypt
from flask import Flask, request, make_response, render_template,\
                  session, redirect, url_for
from oauth2client import client

from google.appengine.ext import ndb
from google.appengine.api import urlfetch
...

I just carious about server side scripts rignt now google.appengine.ext only support on google app engine python runtime? Can I run this project on other server or localhost? or demo in other languages? I didn't find example (less document)

because of I tried to run demo project on localhost and I got error

Traceback (most recent call last):
  File "working/main.py", line 17, in <module>
    from google.appengine.ext import vendor
ModuleNotFoundError: No module named 'google'

Anyone help me please?