"In the event that you are playing with only one local player, your control scheme is "Keyboard 1" (or its equivalent in your current language), and mouse aiming is enabled in the current level or server, you will use the special "Kbd/Mouse" control scheme instead of Keyboard 1. This is preconfigured to allow either arrow keys or WSAD controls, with your primary mouse button serving as an alternate fire key, but you may configure this control scheme just like the other two if you so wish."

Alright, but how/where to change those preconfigured keys? Because I can't seem to use different keys when mouseaim is on. No matter if I change them in game or before I join the server.