I read something about that the quran was compiled and that in some of the non arab lands there was confusion because some people where reciting in other dialects and then uthman had compiled it in one version and then sent it but how? Because before the compiling a lot of non arabs had memoriez it

When the people in the far regions differed in their recitation, Uthman raḍiyallāhu ʿanhu had the Companions copy the Qur’an onto one harf in the dialect of Quraysh, sent a copy to each region with a reciter, and burned the other copies. The people took their recitation from those reciters, because the Qur’an is passed on by memory from teacher to student, not only in writing. Also, don't forget that people used to write other things next to the ayat like their tafseer, so it was feared that people would think these are ayat from the quran, so Uthman may Allah be pleased with him solved that problem by doing so.