Assuming too that you already know about the Wix Pay API and all relevant docs for it.
https://www.wix.com/corvid/reference/wix-pay.html
https://www.wix.com/corvid/reference/wix-pay-backend.html
https://support.wix.com/en/article/corvid-tutorial-processing-payments
https://support.wix.com/en/article/corvid-tutorial-using-the-corvid-pay-api-to-collect-payments-for-a-single-product
https://support.wix.com/en/article/corvid-tutorial-using-the-corvid-pay-api-to-collect-payments-for-products-in-a-database-collection
Plus this tutorial from Nayeli (Code Queen)
https://support.totallycodable.com/en/article/setting-up-wix-pay-api-using-wix-code