<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.3/jquery.min.js"></script>
Can't find variable: $
$(document)
.ready(function() {})
<script src="//ajax.googleapis.com/ajax/libs/jquery/2.2.3/jquery.min.js"></script>
$(document).ready(function() {
Ваш код
});