Civilization VI - derrod/legendary GitHub Wiki
By default Civilization VI will launch the 2K Launcher, which will not recognise the game as being installed. Worse yet, even if it did it would try to run the Epic Launcher again. To work around it you can override the executable Legendary will launch via the config or command line:
Command line
legendary launch Kinglet --override-exe Base/Binaries/Win64EOS/CivilizationVI.exe
Config
[Kinglet]
override_exe = Base/Binaries/Win64EOS/CivilizationVI.exe
Note: If you wish to run the DX12 version use Base/Binaries/Win64EOS/CivilizationVI_DX12.exe
instead.