I've recently done this. You can use PayPal's xclick button, to send custom data (that is, price and shipping) to PayPal. Then the customer will pay via. PayPal PHP SDK is our official Open Source PHP SDK for supporting PayPal Rest APIs. Checkout all the supporting documents, samples, codebase from the. In this video, I will demo how to build Paypal Payment using PHP. To download all sources code for this.