How do I switch wifi channels on the EX7710-B0 router?

Beefanman

There are multiple other wifi channels on the same channel causing interference and I wanted to change channels. When entering the default gateway IP into my browser and entering in the username and password, I get taken to "EX7710-B0 WAN service" which appears to be where I can change settings relating to the PPPoE user and password, IP addresses, and the VLAN ID. There's nothing here to indicate where I should be able to change the channels on the router and no other submenus. Is the router locked to a single channel or am I just missing something?