Hi Andrei Fliser,
Thank you for reaching out gluu support , so what i understood that you are looking to setup SAML SSO but you are unable to see the by default login page of gluu server after installation.
can you please check the /etc/hosts file and make sure its IP address, domain name which you provide during installation are bind together.
also if you install the gluu server without public ssl , then you have to allow browser to make exception to self signed ssl certificate otherwise browser will block the login page.
Please share the screenshot.
thanks and Regards