Hm. I don't see that button at all. At the bottom, these are the only ones shown:



Odd. It's an international business class flight, and I don't see the button for any of 3 different reservations on the same flight. They are UA award tickets, and I got them to come up by entering the ANA confirmation number and passenger name. Maybe it only works for passengers with ANA accounts?

I guess I'll just call them, unless there's some trick to getting the button to show up.