Where can I get information about admission to the "open beta test" STEAM GREENLIGTH?

Question

Steam

Good day.
I found a lot of articles on how to get on the steam greenlight and get greenlight, but I didn't find any documentation about what will happen to the product after the light is received.
Specifically interested in such questions from the server side:
-integration of the payment system
-patching of the game client
-achievement system
-the ability to use other authorization methods inside the game besides Steam (FB and others like them)