The book I'm trying to upgrade is The Legend of the Dragon King. I have the 1 coin, 2 chapter sneak peak atm. I have the maximum Privilege on
another novel, Summoning the Holy Sword. I also tried to access the Privilege upgrade on another novel, Reincarnation of the Business Woman at School, that I also have the lowest Privilege at the 1 coin, 2 chapter level and the upgrade prompt would not show up there either.