How do I put BILLING_KEY for android IAP?

its nowhere in C2, and looking at cocoon.io, there's also no place to put the BILLING_KEY

googling, i keep finding old thread from 2014-2016 with no solution

thankyou

https://developer.android.com/google/pl ... grate.html

https://developer.android.com/training/ ... b-app.html

https://developer.android.com/google/pl ... sting.html

orangpelupa Did you ever get this sorted? Did gumshoe's links help you, because they mean nothing to me.