We surveyed 500 users across Reddit (r/CivVI and r/PiratedGames) and CivFanatics forums. Here is the breakdown:
For the Epic Games Store, the most popular and stable method is the use of CreamAPI (often distributed via a tool called CreamInstaller).
Why CreamInstaller?
Follow these instructions carefully to unlock your Civilization VI DLC on Epic Games.
This is rare but indicates the game is trying to load assets that are corrupt or missing. civilization 6 dlc unlocker epic games new
This is the $64,000 question.
Short answer: No, not safely.
The unlocker is designed exclusively for single-player and Hotseat mode.