我使用ACF插件显示自定义帖子类型（历史记录），在那里我为按钮和按钮链接添加了一个自定义字段。现在，我创建了一个历史帖子类型的快捷码，但我不知道如何添加自定义FID中使用的按钮链接请在此处解决我的代码：

add_shortcode( \'history_shortcodes\', \'history_shortcodes_post_type\' );
    function history_shortcodes_post_type(){
        $args = array(
            \'post_type\' => \'history\',
            \'post_status\' => \'publish\'
        );

        $string = \'\';
        $h_query = new WP_Query( $args );
        if( $h_query->have_posts() ){
            $string .= \'<div class="main_history">\';
            while( $h_query->have_posts() ){
                $h_query->the_post();

                $h_button_field = get_field(\'history_button_title\'); // used to display the custom field 
                if( !empty($h_button_field) ): endif;
                $h_link = get_field(\'history_button_url\'); // used to display the custom field 
                if( $h_link ):  endif;

                $string .= \'<div class="col-sm-6">\' . \'<div class="single_history_img">\' . get_the_post_thumbnail() . \'</div>\' . \'</div>\' . \'<div class="col-sm-6">\' . \'<div class="single_history_content">\' . \'<div class="head_title">\' . \'<h2>\' . get_the_title() . \'</h2>\' . \'</div>\' . \'<p>\' . get_the_content() . \'</p>\' . \'<a href="" class="btn btn-lg">\' . $h_button_field . \'</a>\' . \'</div>\' . \'</div>\';

            }
            $string .= \'</div>\';
        }
        wp_reset_postdata();
        return $string;
    }