After about 5 minutes looking for the button I realized that there was no button but the grey stripe on top of the e-mail changed to purple (if I remember correctly) when I moved my mouse, then I clicked there and there was the question with a YES and NO answer, and of course I clicked YES, I kept the e-mail and now it says that I answered YES, which is great because it means that I didn't make any mistake.
Now I'm waiting for the ticket or what ever they are going to give us, I must tell you that I'm looking forward to it, but bless the operating crew, can you immaging trying to do a service on an aircraft that you don't know and with 500 people walking everywhere taking pictures, its going to be mad for the poor crew, I think that the pax should be giving a sort of "iftar box" and the crew should just stay at the doors and collect the boxes, that way pax can walk freely and the crew can chill out
.
Anyway, enjoy your flight and have a happy and safe one.