What is the earliest statement of the authoritative books of the Bible?

I know that in the land of secular leftism, there are many myths, and those myths survive because they circulate in an echo chamber. But this is the Wintery Knight blog, and on this blog, we go back to the evidence. So what’s the myth? “The list of authoritative books of the Bible was determined hundreds of years after they were written”. Is that true? Let’s take a look at the data and see. So, the allegation is that before 325 AD, people were using the canonical gospels