Genshin Impact received update 1.2, which introduced a new leveling system. You need to search for Crimson Agate crystals and bring them to the Permafrost Tree, increasing its level. In return, you can get blueprints for tools and weapons, experience, a new glider and resources.
To find the Crimson Agate, you will have to explore the new region of Dragon Ridge, where snow and extreme cold await you. Agate crystals are easy to find, as they glow with a sharp, deep red color.
Below is a map showing the exact location of the Crimson Agate.