npm install
npm start
go to http://localhost:8080
https://login.lescommuns.org/auth/realms/master/.well-known/openid-configuration
https://openid.net/developers/certified/
https://www.npm.red/package/openid-client#usage
https://www.infoq.com/fr/articles/introduction-openid-connect/
https://blogs.infinitesquare.com/posts/web/open-id-connect-et-oauth-les-differents-flow-de-connexion
https://medium.com/@robert.broeckelmann/when-to-use-which-oauth2-grants-and-oidc-flows-ec6a5c00d864