If you own the DLC but it isn't appearing, you may just need to "force" the game to recognize it:
Complete specific character towers to unlock specific gear and skins. Conclusion i mk11 dlc unlocker upd top
Acquire the latest updated version of the unlocker from trusted open-source repositories (such as GitHub). Avoid sketchy file-hosting blogs that require completing surveys. If you own the DLC but it isn't