I am trying via a laptop, I have realised it could possibly be because they are flights that I changed to a different date and I am sure when I originally booked them I entered the API then, the new booking still has the old ref number so maybe the computer thinks it is a new booking, I did a little experiment on flights I have booked for next year that I know I have not yet entered the API for and the option on that booking to enter the API was there, so fingers crossed it is that :)but thank you anyway...