Knowing this will help me guide you to the specific files or settings you need to change.
Click the three dots next to the game > Manage > Installation Epic Games Help . Unlock DLC.zip
Right-click Unlock DLC.zip and select "Extract All" or use a tool like 7-Zip/WinRAR to extract the contents to a folder. Knowing this will help me guide you to
Run the game to check if the content is unlocked. Scenario 2: Container File for Downloads ( .dlc ) Unlock DLC.zip