facetwp facetwp_query_args shortcode template filter

custom-hooks.php

<?php

add_filter( 'facetwp_query_args', function( $query_args, $class ) {
    if ( 'gluten_free' == $class->ajax_params['template'] && 'gluten-free-everywhere' == $class->http_params['uri'] ) {
        $query_args['tax_query'] = array(
            array(
              'taxonomy' => 'category', // change 'category' to different taxonomy if needed
              'field'    => 'slug',
              'terms'    => array( 'entertainment', 'travel', 'breakfast-box', 'lunchbox', 'gluten-free-guides' ) // array of term slugs
            )
        );
    }
    return $query_args;
}, 10, 2 );