Hi! Congratulations on your results! I sent mine in last week. How I did it:
While logged in to King's Apply, click on the programme you want to accept. Then, on the menu on the left, click 'view and send messages' and then 'new message' at the top. You can choose 'meeting conditions of your offer' as the category and then upload a copy of your results as an attachment to that message.
I hope that's helpful!