Based on the specification at https://openid.net/specs/openid-connect-rpinitiated-1_0.html
When logging out, this feature will redirect the user to the end_session_url from the discovery document. Their most recent id token will be included in the `id_token_hint` parameter.
To use this, the identity provider must include an end_session_url in the discovery document, and the openid_connect_rp_initiated_logout site setting must be enabled.
Loïc Guitaut
David Taylor
Jarek Radosz