Disclaimer: Make sure to add this to the xbk-options list, and not overwrite the whole list with just this value.
gsettings set org.gnome.desktop.input-sources xkb-options "['caps:swapescape']"Or alternatively, if you do not want to swap Escape and Caps Lock, but simply set the Caps Lock key to be an alternative Escape key, then use the following:
gsettings set org.gnome.desktop.input-sources xkb-options "['caps:escape']"TODO: Investigate if the swap prefix is a thing to swap any two keys,
or if it is just a custom value, and it only exists for swapescape.
Maybe only in combination with caps?