Process payment in external API and validate order payment in VTEX

Good morning,

Does anyone know if it’s possible to implement the following flow:

When sending the cart total to API X, which processes the transaction and returns a success confirmation, we have the payment confirmation but we don’t notify VTEX about the completed transaction. Is there any way to send the payment hash or a similar identifier to VTEX (Payment Notification) in order to ensure the ability to generate the order after the purchase is processed? Or can I only validate a purchase if it’s processed through an API built with VTEX’s Payment Provider?