I installed hardcore darkness 1.12.2-2.0, and there is no config file.
I want to set the mod into mode 2, but I cannot due to the lack of a config file

I have the same Problem. I dont even know what the config file looks like so I cant create it by myself.

Actually, the config file is inside the .minecraft folder, to change the mode just use WordPad in the hardcoredarkness file