Authentification with Google Identity Manager

I tried to setup shinyproxy with the google identity authentification but somehow only google accounts which are specified via IAM are working even though I enebaled authentification via email and created an user with email and password.
Any one knows how to properly setup google identity manager authentification?
My application.yml looks as follows:

proxy:
title: Idetity Manager authentification
logo-url: http://www.openanalytics.eu/sites/www.openanalytics.eu/themes/oa/logo.png
landing-page: /
container-wait-time: 60000
heartbeat-rate: 100000
heartbeat-timeout: 600000
template-path: ./templates/newdesign
favicon-path: ./templates/logo/p42.png
port: 8080
hide-navbar: true
container-log-path: ./templates/logs

#openid authentication
authentication: openid
openid:
auth-url: https://accounts.google.com/o/oauth2/v2/auth
token-url: https://www.googleapis.com/oauth2/v4/token
jwks-url: https://www.googleapis.com/oauth2/v3/certs
client-id: <client-id>
client-secret: <client-secret>


docker:
url: http://localhost:2376
port-range-start: 20000
specs:

- id: test
display-name: test
description:
container-image: test 
container-memory-limit: 5000m