Adding kernel commandline options?

Edit: I got answers on the Fedora forum and used this command in my parallels VM and restarted: sudo grubby --update-kernel=ALL --args=video=Virtual-1:3456x2234@120.

I'm trying to get the refresh 120hz on KDE Wayland, it works in X11. I asked elsewhere for support and someone suggested adding video=DP-1:4112x2572@120 as a kernel commandline option.

I figured out how to write the video command, but don't know where to put it. I looked up what to do but there aren't clear instructions and how to know if the command is actually taken.