Add custom tabs to PowerPack Advanced Tabs module using PHP

code.php

<?php // <-- ignore this.

/** Copy the code below. */

add_filter('pp_tabs_items', 'custom_tab_items', 10, 2);
function custom_tab_items( $items, $settings ) {
    // Add custom tabs.
    $new_items = array(
        array(
            'label' => 'My custom tab 1', // Tab label (required)
            'description' => '', // Tab description (optional)
            'content_type' => 'content', // Tab content type (required)
            'content' => 'My custom tab content 1' // Tab content (required)
        ),
        array(
            'label' => 'My custom tab 2',
            'description' => '',
            'content_type' => 'content',
            'content' => 'My custom tab content 2'
        ),
    );

    $count_items = count( $items );
    foreach ( $new_items as $item ) {
        $item['html_id'] = ( '' !== $settings->tab_id_prefix ) ? $settings->tab_id_prefix . '-' . ( $count_items + 1 ) : 'pp-tab-custom-' . ( $count_items + 1 );
        $items[ $count_items + 1 ] = (object) $item;
        $count_items++;
    }

    return $items;
}