EDF Go electric

I’ve just swapped to EDF go electric 12 month fixed ,I can charge my EV overnight for 7p a kw , but the also advertise a smart charging bolt on so you can also charge during the day at the cheap rate but I can’t see how to add on the smart charging.
I’ve just had a rather confusing telephone call with EDF and the person is spoke to had never heard of it before and couldn’t really help me , is anyone using the smart charging bolt on and how did you add it.