Bible believers, why do you think Moses wrote Genesis?

This question is assuming the Bible is correct, and thus Paul wrote the pauline epistles, Jeremiah wrote Jeremiah etc. So this isn't a discussion about Jahwist, Elohist etc. Many books in the Bible, particularly the NT are anonymous works and were given authors based on random tradition, such as "mathew" writing "mathew" even though nowhere in the bible does it say so. This same thing applies to Genesis. Contrary to other books, such as leviticus, exodus etc, there is zero reason to believe that genesis was written by Moses. For one, it never says he did, nor is he even mentioned once, unlike the other early books, secondly, the entire bible consistently refers to moses as being the one that wrote the "Law" which includes books like leviticus, Deuteronomy, but not once does it mention that moses wrote Genesis, which has nothing to do with the giving of the Law. So what exactly is the reason that christians claim that moses wrote genesis? What is the logic/argument ?