SSID configuration is available at network level.
The GUI is at Dashboard > Network > Click on “Add SSID” (Figure 1) > Enter Network Name (Network can have one or more SSIDs) > Enable SSID > SSID can be configured in router mode or bridge mode (In bridge mode, SSID can also associated with VLAN tag. All traffic from SSID can be tagged when going out of LAN interface) > Configuration Security (WPAPSK, WPA/WPA2) and Encryption (TKIP, AES) for the SSID.
All other wireless settings like client isolation, MAC address filter, SSID broadcast etc are also supported.
Figure 1: Create SSID