Pass the currently queried ID into ajax requests

functions.php

<?php

// See https://facetwp.com/how-to-use-hooks/
add_action( 'wp_head', function() {
?>
<script>
(function($) {
    $(document).on('facetwp-refresh', function() {
        FWP_HTTP.term_id = '<?php echo get_queried_object_id(); ?>';
    });
})(jQuery);
</script>
<?php
}, 100 );


// To access it (within your Query Arguments box)
$term_id = (int) $this->http_params['term_id'];