Doesn't work on LibreWolf. Also can't pin to toolbar. aboutconfig: false doesn't work either. May be limitation in the browser.

just set:
dom.image-lazy-loading.enabled => false
no need this addon.

unlike UnLazy by eladkarako, this one does not work at all, tested with imdb and wikihow, images do not get loaded anything different than before, hope you will take some codes from his extension, and make it nice, nice try tough, hope you add webp images too and indicator how many requests are modified