The redirection URI for client is not registered How to add a new host where i can use the adminportal. I found this.

Create a new conf file /etc/ovirt-engine/engine.conf.d/99-sso.conf and add: SSO_CALLBACK_PREFIX_CHECK=false

then systemctl restart ovirt-engine

This will turn off the additional security check for the callback prefix.

But i want to keep the security and learn howto do it correct. Thanks