I don't have the answer, but I have an interesting story....
I recently won some names registered there (soon to expire) and I couldn't find the AUTH CODES either. When I wrote to them requesting the codes, I got a reply asking me why I wanted to transfer away (but no codes). I wrote them back informing them the main reason was because they didn't accept PayPal and I needed to renew the names soon. Next thing I know, they offer to renew the names for me in advance, and send me an invoice allowing me to pay them back with PayPal.
They really want to keep their customers!
No, I never got the codes, but they were very friendly and my names are renewed now, so I didn't pursue it any further. I'm assuming the only way to get the codes is to contact them because they are not anywhere on the site or domain interface.
*My domains are at "NamesBeyond.com" which is apparently a sister company or partner. The interface says "NameWorks.bz" on the control panel, but the registrar is GoodLuckDomain.