The docs at Use the OIDC Endpoint to Log Users Out of Auth0 indicate that end_user_session should be available in the metadata provided by /.well-known/openid-configuration.
However, it’s not.
Even the provided example doesn’t work:
$ curl --silent https://acme.eu.auth0.com/.well-known/openid-configuration | jq .end_session_endpoint
null
Is this expected behavior?