I’m a member at this site: https://www.christianforums.com/threads/the-bible-73-or-66-books.8006170/
And I like this from the thread I linked:
“But of course we are not talking about Catholic books or even books written by NT Christians in the first century - we are talking about Jewish books... we are talking about the Hebrew Bible and whether the content of it which we have in 39 books... should have been 39 or 50. The Jews say 39 and that was the Bible that Christ had - the one that was kept in the Temple in Jerusalem.
“As Josephus points out the Jews had not changed their Bible in over 300 years. IT is not the Bible of Christ’s day to add 11 books to the Hebrew Bible.
“They ‘knew’ about the 11 books - but they did not add them to the scriptures. The canonized set that had been fixed for over 3 centuries.”
That certainly is one point of view. An alternative point of view is that the Jewish “Septuagint” was 200 to 300 years old by the time of Jesus, and was in wide use by Jewish people throughout the Mediterranean world including in Judea.