Thanks for the link, I will look into it and test the mentioned option.
In my mentioned link, it says
Lumen Global Illumination replaces [Screen Space Global Illumination (SSGI)]. Lumen Reflections replace Unreal Engine 4’s [Screen Space Reflections].
and also says
In Unreal Engine 4, features such as [Screen Space Global Illumination] were not reliable and [Ray Tracing Global Illumination (RTGI)] was not performant for games with a high enough quality, and didn’t integrate with other important systems.
So if I understand correctly, it means Lumen does not use SS algorithms? (I’m not confident now).