How You Log Out of Pass-Through Authentication with Communities Enabled
When Social Experience communities are enabled, customers can log out from the external site, the customer portal, or the community.
Logging out of the external site is the same whether communities are enabled or not, except that customers are also logged out of the communities in the process.
When customers click the Logout link on the customer portal, they are directed to the community logout script using the source page parameter in the PTA_EXTERNAL_LOGOUT_SCRIPT_URL configuration setting. Customers are then logged out of the external site and redirected to PTA_EXTERNAL_LOGOUT_SCRIPT_URL. This setting must contain the fully qualified URL of the page you want to redirect customers to.
When customers click the communities logout link, they are logged out of the communities, redirected to a logout page for the customer portal (ci/social/logout), logged out of the customer portal, and then redirected to the page specified in PTA_EXTERNAL_LOGOUT_SCRIPT_URL.