Season 5 of Fortnite Chapter 2 has a lot of quests and challenges to quickly complete your Battle Pass. Here is the solution for this challenge.
How to bathe in the purple pool of Steamy Stacks?
This challenge is one of week 13 quests challenges of the season. To validate this quest, you just have to go in the direction of Steamy Stacks, northeast of the map. Then you will find a first large building to the west of the city. Go inside, and behind a few doors, you will be able to access to a large sheltered purple pool.
You succeed in this challenge: nothing could be simpler, take the plunge!
You will thus have validated this quest step of the week and thus you collect the 20 XP.