facetwp hightlight searchwp keywords

<?php
/** use searchwp's highlighter on the_excerpt output when using search facet with searchwp engine **/
add_filter( 'the_excerpt', function( $output ) {
    $keywords = '';
    if ( isset( FWP()->facet->facets['search'] ) ) {
        $keywords = FWP()->facet->facets['search']['selected_values'];
        $keywords = is_array( $keywords ) ? implode( ' ', $keywords ) : $keywords;
    }
    if ( ! empty( $keywords ) && class_exists( 'SearchWPHighlighter' ) ) {
        $highlighter = new SearchWPHighlighter();
        $output = $highlighter->apply_highlight( $output, $keywords );
    }
    return $output;
}, 10, 2 );