How to use in app purchases blueprint nodes?

I want to add in app purchases in my game but I don’t know use this blueprint nodes. I could not find source about in app purchases.
example purchases
$1=100 game coins
$10=1200 game coins
$20=3000 game coins
$50=8500 game coins
$100=20000 game coins

Here is the most I could find on the nodes:

Hope it helps =)

sorry I didn’t apply and understand. I need step by step description