Creating mesh collider according to enviroment

I downloaded an enviroment from the asset store and I noticed my character goes through it.
My character is animated and has capsule collider with istrigger unchecked and Every child in the enviroment has mesh collider. I dont understand why My character goes through.
Here is my enviroment : Unity Asset Store - The Best Assets for Game Making
Thank you

If the whole environment is just one mesh, select the environment object, add a mesh collider. if the mesh property of the mesh collider is empty, select the environment mesh as a collider mesh.

If the environment consist of multiple meshes, you have to select all the objects one by one and add mesh colliders to them. If the objects are like simple shapes like a rectangular building, you can use box colliders instead of mesh colliders.