It's not in the YouView menu. It's in the TalkTalk player. Press the big TalkTalk button on your remote, or the TalkTalk option inside the YouView menu.
If you can't get into the TalkTalk player, you need to make sure you are connected directly to the router, and try rebooting both the router and set top box.
If you can't get into the TalkTalk player, you need to make sure you are connected directly to the router, and try rebooting both the router and set top box.