make sure developer console is enabled. i think it's on settings then advanced it should be there idk

open developer console. should be [`] to open it (that little key next to 1 and above tab)

on developer console, type "bind [x] kill" or "bind [x] explode" (remove the [x] and add the desired key you want to bind, recommended k for kill and j for explode) then just press the keys lmao

you successfully killed yourself!!!