You can't. It does not have that facility.
Can I not set up a guest WiFi using my My BT account ?
Neil
Hi distinguished Sage, can I not use my My BT account to set up a guest WiFi ?
Cliff3
No
O.K. so would I have to get a different router to set up a guest WiFi then ?
Cliff
Yes
Remember if you have digital voice or will get digital voice then the hub has to be the first connection to the internet and then any third party router
O.K. thanks. - you don't happen to know what sort of router would allow me to set up a guest WiFi do you ?
One way to do this is to use a WiFi extender that has its own separate WiFi SSID that it broadcast compared to the SSID it connects to the router using. Even better if you can connect one to the router using a cable, as then not only can you use a different SSID, but even different WiFi channels! And if it's a proper guest network, it's easy to turn on and off!