If you haven't posted your story yet, here is a quick guide for how to upload your work to AO3 - just substitute this year's collection, which is Public Call - Doctor Who fic exchange 2018.
If you can't finish your entry by the deadline but think you'll be able to finish with a few days extra, please contact your mods at email@example.com, send in your unfinished draft and ask for an extension. (Please understand that we can't grant extensions without a draft.)
Good luck with the final stretch, everyone! :)