You can now do just about anything you expect to be able to do in a trade forum. To do so, you need to download this tool and add it to your character page in-game. It's all very easy. All you need to do is to paste your shop items in-game using the trade posts button. Just select the items you want to sell, and click the "Make Shop" button.

If you want to sell items or goods, you'll need a unique and a trade post for your character.