Fortinet FortiGate 1U Quick Start Manual page 183

Configuring the Single
Sign-on Agent
If required, select Require authenticated
connection from FortiGate, and add a
password.
You will also enter this password when
configuring the FSSO on the FortiGate unit.
Configuring the FortiGate
unit to connect to the FSSO
agent
On the FortiGate unit, go to User & Device
> Authentication > Single Sign-On.
Enter this password used configuring the
FSSO on the FortiGate unit in the previous
step.
Adding a FSSO user group
On the FortiGate unit, go to User & Device
> User > User Groups.
Providing Single Sign-On for a Windows AD network with a FortiGate 163