JSFiddle - React, Tailwind, and code Playground

HTML

<button type="button" id="hello">Hello</button>
<button type="button" id="bye">Bye</button>

JavaScript

$(document).ready(function() {
    $("#hello").click(hello);    
    $("#bye").click(bye);        
});

        function hello() {
            alert('hello called');
            $.ajax({
                url: 'func.php',
                data: {
                    action: 'hello'
                },
                type: 'post',
                success: function (output) {
                    alert(output);
                }
            });
        }

        function bye() {
            alert('bye called');            
            $.ajax({
                url: 'func.php',
                data: {
                    action: 'bye'
                },
                type: 'post',
                success: function (output) {
                    alert(output);
                }
            });
        }