they might be talking about neocities
you can also set browser.translations.enable to true in about:config for full-page translations. it's kinda slow and the languages are limited compared to google translate, but other than that it's fine. also, it works offline if you install the languages https://support.mozilla.org/en-US/kb/website-translation
Some people spammed CSAM there so the mods shut the community down
theyre 3rd party apps for lemmy