If you mean with a hot emperor, I got you!
1. A Night with the Emperor (no, it's not smut... unfortunately)
2. Seduce the Villain's Father
3. I Don't Love You Anymore
4. The Tyrant's First Love
5. Living as an Emperor's Fiance
6. Empress of Another World
7. Emperor and the Female Knight
8. The Lord of Sun
9. I'll do that Marriage
10. I don't want to be Empress
(Let's leave it at that for now. If that's not what you wanted then no problem, just ask)
If you meant something that almost the same storyline as this I recommend "Sincerely, I became the maid of the Duke".
I think it's already completed on raws, but not in the translated one.
Anyone got recommendations like this? Asking for a friend...