Finding a manhwa

It was about an author that got transported to another world, but she's also an inventor. It's not "as you wish, prince.". She's really cool and when first meeting the (I think he was a prince, I forgot) prince she cross dresses and continues to do so for a long time. The prince when she first meets her wants to kill her but the prince also has a great fascination for inventions. Eventually she convinces the prince and she becomes a great asset. Later there is a jealous fiancee that comes and doesn't like the mf, but they get along at the end I think. There is a lot of trust with the soldiers with her as well. Please help me find itt, I her a strong female lead and I've been itching to read this manhwa again, it's so good.
(๑•ㅂ•)و✧