Expand the Persistent Agent folder. Select USB Detection from the tree.
Reference: [Reference:https://docs.fortinet.com/document/fortinac/8.5.2/administration-guide/814147/usb-detection, , 1. Click System > Settings., 2. Expand the Persistent Agent folder., 3. Select USB Detection from the tree., 4. Click Add or select an existing USB drive and click Modify., ]