feature sign

add_filter( 'jnews_featured_image', function ( $image, $post_id ) {
    if ( jeg_metabox( 'jnews_paywall_metabox.enable_premium_post', false, $post_id ) &&  is_single() )  {
        $image = rtrim($image, '</div>') . '><div class="premium_sign">+</div></div>';
    }
    return $image;
}, 999, 2 );