FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
Article Id 192757
This article explains how to list all the services of the Internet Service Database with their respective IP ranges, protocols and ports.

To identify the services contained in the database, run the following command:
# diagnose internet-service id

This will provide the ID number and name of the service. 

Use ‘grep’ to find the ID of a specific service.  For example, to identify the ID of FortiGuard, run
# diagnose internet-service id | grep FortiGuard
ID: 1245324 name: "Fortinet-FortiGuard"

Once the service has been identified, the ID can be used to find the protocol and ports:
# diagnose internet-service id 1245324

Version: 00004.00067
Timestamp: 201705291030
Number of Entries: 2
Internet Service: 1245324(Fortinet-FortiGuard)
    Protocol: 6 Port: 443 8889 8890     <---- Ports and protocols being used by the service
        IP range(34):
    Protocol: 17 Port: 53 8888
        IP range(34):

If the IP ranges are not shown, add the Internet Service to a firewall policy rule or static route.