As I have a FortiAP, I will add that to the FortiGate
To do that, connect the AP to one of the LANs on the FortiGate, then configure the port as you would for a LAN, but make sure for Administrative Access, select Security Fabric connection as this will allow the FortiGate to see the AP when connected
Once that is done, go under WIFI & Switch Controllers → Managed FortiAPs
You will see the AP greyed out and you have to authorize it to use it

Now to use it, we need to create FortiAP profiles, which is found WIFI & Switch Controller → FortiAP profiles, then create New
As my AP as two radios, one will be a monitor and one will be 5Ghz


I added the SSID i will be using for this AP, and for power I selected range as I don’t want to use full power.
Now to create an SSID, go under SSID for WIFI & Switch controller and create New
