I'm using FacetWP, a WordPress plug-in. It's well documented but I'm not getting the following right. I wan't to set a limit on the amount of checkboxes that can be selected.

I set up this test environment: https://hostingsites.nl/webhosting-vergelijken-medium/

You can see 3 checkboxes here. It are no default checkboxes so solutions like this: http://jsfiddle.net/gbrodzik/vVxM2/2229/

I allready tried and can't get them to work properly:(

I read the documentation and I got to the following script:

<?php
add_action( 'wp_head', function() {
?>
    <script>
        (function($) {
            $(document).ready(function() {
                $(".facetwp-checkbox").click(function () {
                    if (FWP.facets['hosting_provider_naam'].length = 2) {
                        event.stopImmediatePropagation();

                    }
                });
            });
        })(jQuery);
    </script>
<?php });

Now I cant select any checkbox so something is wrong with my if statement and I can't seem to find out what I am doing wrong.

Anybody got an idea what is wrong with my code?