I think the setup will be the same as in FGT, like it's shown here: https://community.fortinet.com/t5/FortiGate/Technical-Tip-Set-up-SAML-admin-LDAP-login-on-Fortigate-...Fabric Connectors [Security Fabric Setup] > Single Sign-On Settings
Like Emirjon said it should be the same.
You can find official cli reference here:
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.
Copyright 2023 Fortinet, Inc. All Rights Reserved.