it

it says i'm missing N3x7xp: Thief Top and Horn fix, where can I find this?

When missing mods, try using a search engine for what you seek: https://sideload.betterrepack.com/download/KKEC/Sideloader%20Modpack/N3x7xp/

The link you posted to does not have the mod mentioned by the other commenter.