I just wanted to know if I can bypass the SSO authentication putting "?failover" after my JAMF console URL then what is the point to use SSO, or it is known to administrator only not for others? Or it can be stopped also to bypass in this way?
The whole point of having the failover is if your SSO provider isn't working properly and you can't login then you use the failover so you can still login to your Jamf Pro server. The whole point of having a SSO is to only allow authorized users to login to your Jamf Pro server.
That was a long concern about the failover login as it was the same for every Jamf instance. Now you can generate a random URL that is unique to your instance. Go in to Settings -> Single Sign On. Click edit and click the regenerate button. Take note of the URL that is generated. If you every need to login with a local account (like your "break glass in case of emergency" account) you will need this random URL.