I remember when I read it was just a promo, I’m not sure if it has a serialisation yet. The story goes something like this as I can remember:
-MC (a princess) reads a book in the library which are similar to the events happening
-while she’s reading (I think) she gets taken by knights and she realises it’s similar to the events in the book
-her half brother (I think) has decided to overtake the throne and was about to kill her but she tries to convince him to change his mind but gets killed
-comes back to the library again where she was and same event keeps occurring
-keeps on dying while trying to convince her ‘half brother’
-gets tired of the repeating process of dying and coming back so says something to praise him instead and ends up not dying that time (?)