Goal

You only want your Jira Service Desk customers to be logged in via SSO.
Regular Jira- Software or Core users should still see the default login prompt.

Solution

• In the Redirection section of the SAML SSO configuration, enable the Redirect SD Customer Portal checkbox only

• Make sure that the Enable SSO Redirect option remains unchecked

• In the Logout section set Logout Redirection to Redirect only SSO users after logout

• Save your settings

From that point on, customers who are accessing the Service Desk portal via https://<your-jira-instance>/servicedesk/customer/ will be logged in via SSO.