How to disable SSID broadcast

I installed my Orbi CBK40 yesterday - installation was easy and it works great on Xfinity - much faster downloads. The only question I have - how do I disable SSID broadcast? There is no "Enable SSID Broadcast" check box in the Basic - Wireless Settings admin window to uncheck. My firmware version is V2.3.5.12_1.0.8 in case that makes a difference. Thanks!