You can provide the configuration details for Single Sign-On in Freshservice under Admin-->Helpdesk Security-->Single Sign-on. Here you can provide the details for either Simple SSO or SAML SSO.
For Freshworks accounts:
Admin -> Helpdesk security -> Manage Helpdesk Security from Freshworks 360 Security and configure one or multiple Sign in options.
This configuration is only available for the organizational administrator to configure and even account administrators will not be able to access this feature.