I'm sorry. I don't have enough information about your system to fully help you. The idea is to install the `nvidia` driver through the command line though. Please google a little about installing the nvidia drivers for your distro.
Alright you'll want to install the proprietary nvidia drivers on your OS. I can't quite pinpoint what OS you are using currently. You said you were using KDE Plasma, but more than one OS uses it. Are you using something like Kubuntu?
Hello. You cannot use the `nouveau` driver to run Minecraft on Linux. Please use the proprietary driver for your graphics card. You can find this setting with the "additional drivers" program/setting on Ubuntu the last time I checked.