From FortiSandbox side nothing special to do, it works as normal ICAP. From Forcepoint side please check if there are any additional requirements ex.: license or special configuration that needs to be done.
Best Regards Konstantinos Agritelis Fortinet EMEA TAC Engineer
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.