Cube Agree GTC - Tri-Bars
Based on the review, it simply sounds like the cross-section of the bar is different than a usual bar. So, if you want to attach tri-bars to the bike, you may need to get a new drop bar (which has the usual circular cross-section), and then attach the tri bars to that bar. 

Of course, if the bike works well with the new drop bar and tri bars are all highly a function of you and the particular bike, which we can't really determine over the internet - You'll probably just have to try it or get advice from your LBS on it, since they can probably fit you in a tri-position.