Click on "FORUMS" on home page (or above) scroll down to "MEMBER CLASSIFIEDS" (Last category) tap on it & when it takes you there the red tab in upper right corner should allow you to post an ad. Red tab says "Create Post" or something close.
You do. And you posted in the classifieds already, just not an add to sell something. WTS is want to sell. Do it the same way and tell us what you want to sell.