¿Cómo realizo la compra y el pago?

<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet"><link href="https://fonts.googleapis.com/css2?family=Nunito:ital,wght@0,200;0,300;0,400;0,600;0,700;0,800;0,900;1,200;1,300;1,400;1,600;1,700;1,800;1,900&display=swap" rel="stylesheet"><!-- Start of app.ringow.com Ringow Widget script --> <script>var showringow = true;
if(window.location.href.indexOf("crear-cuenta-demo-app") !== -1 || window.location.href.indexOf("registro") !== -1) { showringow = false;
}
if(showringow === true) { (function () { var jrw = document.createElement('script'); jrw.type = 'text/javascript'; jrw.async = true; jrw.id = 'nwRtcMaker'; jrw.src = 'https://app.ringow.com/ringowStart?id=2&key=66480'; var srw = document.getElementsByTagName('script')[0]; srw.parentNode.insertBefore(jrw, srw); })();
} </script><!-- End of app.ringow.com Ringow Widget script -->