JSFiddle - React, Tailwind, and code Playground

HTML

<form method="POST" id="ajaxform">
    <label for="test">Test Input</label>
    <input type='text' name="test" />
    <button type="submit" id="mainbutton">Submit</button>
</form>

JavaScript

$(document).ready(function(){
    $("#ajaxform").submit(function(e) {
        e.preventDefault(); //STOP default action
        var postData = $(this).serializeArray();
        var formURL = $(this).attr("action");
        $.ajax({
            url: formURL,
            type: "POST",
            data: postData,
            success:function(data, textStatus, jqXHR) {
                alert("success");
            },
            error: function(jqXHR, textStatus, errorThrown) {
                alert("error");      
            }
        });
    });
});