It's week 9 of Chapter 2 Fortnite season one, which means more challenges, and the wide variety of those allows you to earn a lot of XP for upgrading your Battle Pass.
This week's challenges are to search chests and ammo caches, damage enemies, do a time trial for motorboats, and dance on bridges. Once you've completed all of the Chaos Rising challenges, you unlock the Chaos Rising loading screen to find the XP trace hidden in the picture.
If you look closely at the Chaos Rising loading screen, you can see that the hidden XP drop is next to Kevin the Cube. You can find a statue of Kevin the Cube outside of Steamy Stacks.
All you have to do is complete all eight challenges and then head to Steamy Stacks. Kevin's statue can be found in the parking lot in front of the building and is next to the hidden XP dropper.
If you need help completing the other challenges and receiving the hidden XP, we have The helpful guides on The Three Bridges You Must Dance On Location And The Motor Time Trial. If you still have some work to do to complete your Battle Pass, remember that the season doesn't end until February. You have plenty of time to complete it before the start of the next season.