test for OAuth2 and get accessToken & idToken , now has 2 provider : google / facebook
you need public domain for test this, and must use https, so easiest and no cost way is raspberry pi as host and use cloudflare
and copy .env_backup to .env to run it, here only very simple code to get accessToken & idToken, and some doc you may need know, like this
https://auth0.com/blog/id-token-access-token-what-is-the-difference/
if you are doing sso providers, simply use idToken will be a good choice.