Editing the wiki (reading doesn't require a login) or logging in to the Goods to make a trade requires you to set a password ingame. The password database for out of game websites is kept on atitd.net and is not controlled by eGenesis.
To do this, log in as the character you want to use and type /webpass atitd.net password, replacing password with a password of your choice (a good security measure is not to use your ATITD password, but it should mostly be safe).
You'll get a pop up to confirm that the password was sent to the atitd.net servers. You should then be able to log in to the wiki and to the Goods using your character's name and the password you set.