load jquery

load-jquery.js

// Anonymous "self-invoking" function
(function() {
    // Load the script
    var script = document.createElement("SCRIPT");
    script.src = 'https://code.jquery.com/jquery-3.3.1.min.js';
    script.type = 'text/javascript';
    script.onload = function() {
        var $ = window.jQuery;
        // Use $ here...
    };
    console.log(script);
    document.getElementsByTagName("head")[0].appendChild(script);
})();