Even if you avoid a platform ban, downloading and running unsigned, third-party software from unofficial forums is a major security risk. Many of these tools are distributed via file-sharing websites, which can be a hotbed for malware.
The most straightforward and verified way to access all the DLCs for Civilization 6 is to purchase the Civilization 6 Complete Edition. This edition includes the base game and all the DLCs, including expansions, game modes, and other additional content.