Hi @sven https://openid.net/specs/openid-connect-rpinitiated-1_0.html states regarding the logout endpoint: "OpenID Providers MUST support the use of the HTTP GET and POST methods defined in RFC 7231 [RFC7231] at the Logout Endpoint. RPs MAY use the HTTP GET or POST methods to send the logout request to the OP."
I need to check, if the POST method is actually implemented. FYI @livio
@Sinan I think I found a problem that could be the root cause for the issues with POST requests https://github.com/zitadel/oidc/pull/632. I could be wrong but I think it's rather the content-length header that's causing problems than a missing CORS header.