Let me first assume this is just an "English as a second language" moment and point out that "make up a story" would mean to invent one, to imagine a scenario. So, assuming that's not what you mean, I'd just advise you to not use that phrase in this area.

Now, let's also assume it is what you meant. Don't! If you just make up a story, a good interviewer is likely to spot it. Heck, even when I make up stories for some of the fiction articles I write, I base the technical stuff on things I've actually seen and done. They need to know what you know and understand what you've done and how you've done it. They're not hiring you for your ability to make up a story. But, the ability to tell a story with lots of details is something they are hiring your for.