As appgyver team informed me, there is no official support of in app purchases.
After research I found this cordova plugin which seems the best solution out there.
I added into the android build through the cloud build service and I checked that exists into the produced apk.
Now I want to test it but I can not find any usefull guide that explains which additions must be made into my source code and how I setup and call the services of IAP.
I would be grateful if anyone help me...