add_ebay_store_category.php

<?php
require __DIR__.'/vendor/autoload.php';

use \DTS\eBaySDK\Constants;
use \DTS\eBaySDK\Trading\Services;
use \DTS\eBaySDK\Trading\Types;
use \DTS\eBaySDK\Trading\Enums;

$service = new Services\TradingService(array(
    'apiVersion' => '941',
    'siteId' => Constants\SiteIds::US
));

$request = new Types\SetStoreCategoriesRequestType();
$request->RequesterCredentials = new Types\CustomSecurityHeaderType();
$request->RequesterCredentials->eBayAuthToken = '';

$request->Action = 'Add';
$request->ItemDestinationCategoryID = 14122;
$request->DestinationParentCategoryID = 14125;

$request->StoreCategories = new Types\StoreCustomCategoryArrayType();

$category = new Types\StoreCustomCategoryType();
$category->Name = 'MP3 Players and Accessories';
$category->Order = 1;
$request->StoreCategories->CustomCategory[] = $category;

$category = new Types\StoreCustomCategoryType();
$category->Name = 'GPS Devices';
$category->Order = 2;
$request->StoreCategories->CustomCategory[] = $category;

$response = $service->SetStoreCategories($request);

if (isset($response->Errors)) {
    foreach ($response->Errors as $error) {
        printf("%s: %s\n%s\n\n",
            $error->SeverityCode === Enums\SeverityCodeType::C_ERROR ? 'Error' : 'Warning',
            $error->ShortMessage,
            $error->LongMessage
        );
    }
}