Troubled Times: Travel into the Book You Wrote

[Alternate History] Shen An, who was unemployed in middle age, turned to writing novels, but even signing a contract was a problem. On his way back home, he accidentally wandered into a new book he was contemplating. Broken! He only planned the final years of the fictional dynasty and the general pattern of the world. I haven't decided who the protagonist is yet, and I haven't started writing the story yet. Fine! He has a shopping mall system. However, the amount of money in this mall is a bit bullying for novice authors.