Plugins
Indico provides many plugins that can be used to extend functionalities without the need to change the Indico core. See more information in Extending Indico with plugins.
You can configure additional plugins using the external_plugins configuration option.
There is a special treatment for the Flask-Multipass-SAML-Groups plugin:
When this plugin is installed, the charm will automatically configure Indico to use the provided custom Indico Identity Provider saml_groups if a saml integration is available.