Sign-In System: Being Forcibly Married by the Demonic Empress at the Beginning

With a single female protagonist, the first part is about a fantasy world, and the second part is similar to the female protagonist (a domineering female CEO) falling in love with the male protagonist (a college student). Both the front and back are sweet, and there is also a plot of cultivating immortality before and after. This novel is quite interesting. It's the first time I've seen this kind of writing. I've read nearly 400 chapters. I don't know what to do next.