JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Test Page</title>
</head>

<body>
	<button type="submit">PUSH!</button>
</body>
</html>

JavaScript

$('button[type="submit"]').click(sendForm);
function sendForm(e){
  e.preventDefault();
  $.ajax({
  	crossDomain: true,
    method: "POST",
    url: "https://fierce-hamlet-20612.herokuapp.com/mail.php", 
    data: 'testdatastring'
  })
    .done(function(data){
    alert('Data: *** '+data+'***');
  })
    .fail(function(){
    alert('no data');
  });
}