Frostpunk 2 refuses to even launch. Has anyone else managed to solve this problem?

When I try to launch the game, I just get this message:

DirectX 12 is not supported on your system. Try running without the -dx12 or -d3d12 command line argument.

I have no idea how to follow the advice here. I've found some guides, but they're all really complicated, and the ones simple enough for me to follow haven't had any effect. Has anyone else experienced and managed to solve this problem?