This documentation is not using the current rendering mechanism and is probably outdated. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.
How can I use tt_news together with wt_cart?¶
If you want to connect tt_news with wt_cart we recommend using a small extension called 'ttnews_wtcart' This extension can be downloaded from TER. It works together with tt_news version 3.x.