OK, I got my ticket and, as @
mannimagus and others have said, the answer is yes you can.
Of course my situation is a bit more complex because the first leg of my flight (KBL-DXB) is operated by Flydubai which means that I have the following message in the MMB section "You cannot purchase excess baggage for this flight, as it is not operated by Emirates, or you are connecting to/from a flight not operated by Emirates". On top of that when I called EK they said that I should deal with FZ and when I called FZ they said I should deal with the travel agency who booked the ticket
Thanks for your help folks.