ᐅ Can a radon barrier be installed directly on the screed in the basement?

Hello, we are currently renovating the basement of our previously owned house and are wondering if we should or can still install a radon barrier.
As far as I remember, the membrane is placed directly on the concrete slab, and then the floor construction (screed, etc.) is built on top. However, the screed is already installed, and we do not want to remove it.
Is it possible to lay the radon barrier on top of the screed and then install the floor covering?

Thank you for your help.