Could you please explain some more details?

Payment can be definitely build via API. But could please explain more requirement regarding RingCentral

Currently, our website calls an api from paypal where the paypal server takes the credentials from the user and applies the "sale" to our paypal account. The success of this is returned to the website via the api. Thus, all financial transactions are done via the paypal server. Is there such a paypal api add-in to accomplish this via an incoming call?