KASU here! I aksed my friend and she told me this::
Oh submiting fanfiction on deviant huh? Hm. Its like this:
When submiting the art, you must click the 'add text' button and categorize the fanfic under fanart>fanfiction> your choice
Also when you want to put things (like bold, italics and centering) , read this to know how to do it:
---> link:
[link]