Microtransactions for Steam: Finally an answer is needed

Hello I have been asking this question since like November 2017 so please help me.
There is NO knowledge over the internet, no one shares how to do that,
I KNOW how to add Steam, I HAVE achievements.
But achievements are not Microtransactions
Please someone indicate whether its at all possible in UE4, and with blueprints
Don’t send Epic tutorials on how to integrate Steam. I have steam and achievements. But achievements are not Microtransactions
How to add microtranzactions. Someone help. Does anybody at all knows how to do that? There is zero documentation, 0 videos, 0 threads over the internet about that(except my threads)