I recently made a post about why not to use Paypal. The worst kind of governments that decide they will fine people for speaking the truth about the dangers of taking the COVID jab. Later this is still denied by self proclaimed "fact checkers". For Paypal to go along with that makes them a participants in a crime against humanity. Are you going to support those involved in a crime against humanity by working with them? We should be ostracising them at least until they get the real justice that is coming to them.
Why keep Dollars in Pay Pal when you can keep Dollars in Hive? I came across the user 
There is a developer link for gluing it's purchase flow into an application you may be developing and it includes IPN.
The Hive or Hive Dollars, or Hive Engine Assets are credited to the merchant's Hive account. To me it seems, the money would go to Hive Pay and then after the fee is deducted it would go to the merchant.
Alternatively, this could have been done with a multi-operation transaction. If using Hive Keychain, there could be one operation that sends to the merchant and another operation that sends the fee. It is part of the transaction, so both operations would happen or neither would happen. It isn't complicated to the user if using hive keychain which prepares it and gives it to the user to sign.
The Hive Pay site if possible should have a sign up part, and creditcard on-boarding to the site. That is, if the user doesn't use Hive for some reason, they should be able to use their debit or credit card to pay via Hive pay. This last thing would enable this project to really take off. It would be really cool for fiat payments to go from the customer into my Hive Dollars. Instead I suggest you have three back ends: For Hive blockchain assets, use Hive Pay. For altcoins, use CoinPayments.net and for fiat use stripe.
