It is a beautiful find; it is very similar to the edible Agaricus subrutilescens. ππ
If so, they can produce very artistic-looking spore prints that will help validate the mushroom. If you place the cap on white paper and cover it with glass, you will note the dark chocolate print after a few hours (if it is the Agaricus S. )
This link below will give you an idea of the poisonous lookalikes.
https://morrie2.com/category/fungi/inedibles-and-look-alikes/