UE 4.22 SSGI not working (scren space global illumination)

hi
i downloaded the UE 4.22 dev-rendering from this link at github: https://github.com/EpicGames/UnrealEngine/tree/dev-rendering.
build it using VS 2017, the editor is starting just fine but i can get SSGI to work for me, there is no commande line showing for r.ssgi, if i’m missing something please guide me throught the process.