Pulbishing original stories on ao3

I have been writing an action mystery novel about my ocs for a while now and lately I've really started to consider publishing it on ao3, but I don't know for sure if it will get any attention since the site is normally used for fanfics.

I haven't seen many original works there, does anyone know if publishing my story chapter by chapter would be a good idea?

The draft I'm still writing is like 137 pages long right now, and I've been considering to divide it into small parts and publish it on the internet. 

If there are websites that are more suitable for newbie writers like me pls lmk! Anything other than wattpad will do. 

Logging out!