I often check a few days before travelling for discounted upgrade availability using the code as emailed out, even if I haven't been emailed (it's a generic code).

I used to access this by going to the Manage a Booking log-in page via the Plan and Book menu, which gave you a box to enter the upgrade code. Going to Manage a Booking directly from the front page of the website took you to a page without this box.

This route is no longer available as the page no longer has the option to enter a code. Can anyone tell me an alternative way to access this and try out the code?