Custom sort box (radio) -- event handlers not included

functions.php

<?php

add_filter( 'facetwp_sort_html', function( $html, $params ) {
    $html = '<div class="facetwp-sort-radio">';
    foreach ( $params['sort_options'] as $key => $atts ) {
        $html .= '<input type="radio" value="' . esc_attr( $key ) . '" /><label>' . esc_html( $atts['label'] ) . '</label>';
    }
    $html .= '</div>';
    return $html;
}, 10, 2 );