How to join a Queue without using the bot? (XEP 0142)

Hello everybody,

I recently started using XMPP and openfire with fastpath.

Right now I am writing my own client that should be able to generate a "support request".

I know I can simply send a XMPP Message to a workgroup and the bot will ask me some questions....however, in XEP 0142 specifications (http://xmpp.org/extensions/xep-0142.html#roleresp) is written that there is a iq we can use to join.

However, openfire always sends me a error 500 internal-server-error.

Do I have no other choice but to use the bot?

Thanks in advance!