Hi Sandeep,
Thanks for reaching out.
For the issue you are getting, did you try accessing google login URL (https://accounts.google.com/o/saml2/idp?idpid=C04k3fo2d) directly? This won’t work, instead, you need to initiate SSO from SSO link on the WordPress site.
You can use the link below for SSO.
https://<wordpress-url>/?option=saml_user_login
The feature you have mentioned (auto-redirect, advanced attribute and role mapping) are supported in our premium version. If you want to try out our premium plugin, we can setup a demo on our cloud environment and can provide you with the access.
Looking forward to your reply.
Thanks,
Kalpesh