the novels extra

The Novel's Extra is a popular Korean web novel by Jee Gab Song that popularized the "isekai into a novel" trope.
Kim Hajin wakes up trapped inside an unfinished novel he created. Reborn as a background "extra" with no plot armor, his only way home is to survive by following his own storyline. However, he soon realizes the fictional world has unpredictable deviations from his original draft.