All my modules require users to be registered to add listings or to reply to a listing.
There are parts that NEED a user ID. to work properly.

All reputable websites DO NOT allow anonymous users to add anything, even on the
Xoops site you need to be registered, there are many reasons for this.

You may be able to hack the module to work with non registered users, it will probably not be easy, and I do not support this. I'm sorry but thats the way it is.