jQuery code before footer

Hello,

I use this plugin in combination with Contact Form 7.
After I enabled the plugin, the following code will be added before the footer.

Now I get the error “Uncaught ReferenceError: jQuery is not defined”, because the script below will be loaded before the jquery embed script.

Do you have a solution for this problem?

Thank you!

<script>
    jQuery(document).ready(function($) {
        var $checkboxes;
        function storekey() {
            var keysVal = $checkboxes.map(function() {
                if(this.checked) return $(this).attr('data-key');
            }).get().join(',');
            $("input[name='fieldVal']").val(keysVal);
        }
        $(function() {
            $checkboxes = $("input[class='listCheckbox']").change(storekey);
        });
    });
</script>