Editing a language in a mod via datapack

The short version is that I'm trying to edit a lang file, but it doesn't seem to be working. I've made several datapacks before, but never messed with anything in the assets folder, and it seem to be giving me trouble. The specific lang file is for the End Remastered mod. I just want to change some of the eye lore. Is my file pathing off? Do I need to do something different with a lang file that I don't have to do for, say, a crafting recipe?