Locate wifi clients when not connected

Hey,

We are using a Forti 100F as a firewall and have several FortiAP 231F in different locations. These are all on the same network and directly connected. Now the question is, is it possible to use the "locate wifi clients when not connected" feature without an extra server and without using Aeroscout (because we don't want to use another server for that). If so, is there any documentation on what needs to be done to use this feature, or does it just need to be enabled? Another question would be where these disconnected clients are listed and how to distinguish them from the "normal" connected clients.

Thanks for your help!