Last time I flew back on BA from Dubai I didn’t get any duty free at the airport as I thought I’d get it on board but they said they no longer do it.

How does this work then? I can purchase it on Highlife but when does it get delivered? Is it back on board or are there any plans in this direction? Otherwise I’ll just get it before departure but I used to prefer doing it on board to give the commission to the cabin crew.