Metabox connect don't work

Metabox problem how do I connect these php in this code, what am I doing wrong

elseif($infobox_type == 'cspm_type5'){

    $output .= '<div class="cspm_infobox_content">';
    $output .= '<div>';
    $output .= '<div class="cspm_infobox_img">'.$post_thumbnail.'</div>';
    $output .= '<div class="title">'.$the_post_link.'</div>';

    <?php echo get_post_meta( get_the_ID(), 'barcode', true ); ?>

    $output .= '</div><div style="clear:both"></div>';
    $output .= '<div class="description">';
    $post_record = get_post($post_id, ARRAY_A, 'display');
    $post_content = trim(preg_replace('/\s+/', ' ', $post_record['post_content']));
    $output .= apply_filters('cspm_large_infobox_content', $post_content, $post_id);
    $output .= '</div>';
    $output .= '</div>';
    $output .= '<div style="clear:both"></div>';
    $output .= '<div class="cspm_arrow_down"></div>';