Student or Learner
It was here that Rouling completed Harry Potter and the Philosopher's Stone. It/That was the first of the seven books she had planned about a boy and his life at a school for wizards.
Do both it and that fit in the above context? Thanks.
That refers to something far away.
You are referring to the book that she wrote which was immediately preceding the sentence where this is used.
It might be used. But you used "it" in the previous sentence so there could be confusion also using "it" so soon does not sound very good.