How refraction work in PlayCanvas


I don’t understand how refraction works in material properties.
This is only a false reflection of the environment cubemape in backface culling, but does not affect the objects behind it at all, transparent or not. The refractive index does not work.
Yet it seems to me to be a simple physical property.
And I didn’t find any documentation on this subject on the site.
Would you have any documentation on how to do something realistic please?