unable to build lighting properly

Hello. I am following this arch-viz tutorial. Everything was going smoothly until this point. I am facing an issue with baking shadows using skylight only. Am using an HDRI in an SLS cubemap in the skylight.
The person who made the tutorial is using a GPU with raytracing capabilities and is able to run GPU lightmass properly. I am unable to do so as I have an Nvidia 1050ti which does not support raytracing and therefore cannot seem to run GPU lightmass.

I have 2 questions.

a) How do I get this output?

b)Is there any way GPU lightmass can function properly on my GPU? If yes, then how?

Shall be grateful to solutions to these issues.