I setup Paypal billing in my backend .(I avoided to do integration in the android client because google prevent thirdparty payment),
1- the client only register a record in my server
2- i setup a trigger to make an order an to generate a new orderId
3- status : PAYER_ACTION_REQUIRED, and the user have to make payment
the problem that the webhook i set up in my app do not trigger my endpoint in the server to complete order
1- searching in paypal community with no hope
2- turning my sandbox account into live
3- checking my endpoint using postman that was correctly working