So the page https://moodle.org/mod/data/view.php?id=7232 (having logged in) says...
"You need an account on moodle.org in order to post an advert. Login then click the "Add entry" tab. Adverts require approval before they are viewable by everyone. A pink background to your advert indicates that it is awaiting approval."
So clearly I have an account but the advice above needs updating as thats clearly not enough. I can see no "add entry tab"