Please use the GNUnet installation guides.
The easiest way to manage OpenID Connect client is through our CLI tool:
$ gem install reclaim-oidc
  To register an OpenID Connect client, execute:
$ reclaim-oidc --add --client-name myclient --redirect-uri https://mywebsite.com/oidc_cb --description "My Client"
  You can list all registered clients and your local OpenID Connect metadata required to initiate an authorization code flow by executing:
$ reclaim-oidc --list 
  The response will look like this
OpenID Connect Provider Information:
  ------------------------------------
  Authorize Endpoint: http://localhost:7776/openid/authorize
  Token Endpoint: http://localhost:7776/openid/token
  JSON-Web-Token Algorithm: HS512
  JSON-Web-Token key: secret
  Example Authorization Redirect:
  https://api.reclaim/openid/authorize?client_id=<client_id>&redirect_uri=<redirect_uri>&response_type=code&scope=email%20full_name&nonce=1234
  
  Registered Clients:
  -------------------
  name: myclient
  client_id: <client_id>
  client_secret: <client_secret>
  description: My Client
  redirect_uri: https://mywebsite.com/oidc_cb
  ...
  
  You can use the information above to integrate re:claimID as a generic OpenID Connect Identity Provider into the web application of your choice. The integration steps for this part depend on the application you use. Hence, please refer to your respective documentation or the OpenID Connect specifications.