The Secret of the Scorching Desert quest involves a puzzle where you have to rotate three pillars inside a mysterious ruin to progress.
Mysterious Ruins Domain & Puzzle Guide | The Secret of the Burning Desert | Genshin Impact version 3.1
The Sumeru region has a sand dune area where you can do and complete the Archon quest "Secret of the Scorching Desert". In this mission you are asked to go over to a specific location indicated by the mission tracker.
The place is actually a mysterious ruin, and inside you can find a pillar puzzle that you need to solve to proceed. We will talk about how you can solve that puzzle in this guide.
The mysterious ruins in question are King Deshret's mausoleum which you can find in this part of the map:
