At the Exec Club landing page. The old GUI let you select "Pay With Miles" etc. from the drop down, as well as with cash. But it seems to have vanished suddenly. (Maybe they have retired the miles booking search function temporarily owing to it being knackered?).

That GUI was also cool in that I could just input the airport code directly (eg DXB). But now I have to do all that boring select-country rubbish.

On the plus side, at least the airport drop-down spares me from the MAN "you mean Managua?" irritation.