Implement in app purchase?

Hello community!
Sorry for the millions of questions, still somewhat a noob and I’m very interested in the unreal engine software. On one of my games I’m nearly finished with, I want to implement in app purchase. So my question would be how would I do this? The purchase would allow the player to have more credits. I’ve looked around on different forums and similar questions but no for sure layout of how to do so. I’m using version 4.10 if that helps.

Screenshots would be awesome if someone could help.

I already have a developer account on android (google playstore)
if needed to prevent answers regaurding that or if I need information from that account