Some payment methods, such as bank transfers, do not return to the server after completion. These
methods, termed “Push Payments,” involve presenting the user with payment details (like a QR code),
after which there is no return to the merchant page. The transaction is an open order,
with the payment being pushed to the order asynchronously by the buyer.
In Embed, a push payment immediately completes using the onComplete without presenting
the buyer with the approval URL. Link the transaction ID to the order,
and then either redirect the user to the approval_url on the transaction, or present that
same URL in a popup or <iframe> if possible.
