$client = new \GuzzleHttp\Client();
$url = 'https://api.psiproductfinder.de/v2/products/update/v-88c62663';
$response = $client->patch(
    $url,
    [
        'headers' => [
            'Authorization' => 'Bearer {YOUR_BEARER_TOKEN}',
            'Content-Type' => 'application/json',
            'Accept' => 'application/json',
        ],
        'json' => \deepclone_from_array([
            'classes' => 'stdClass',
            'objectMeta' => 3,
            'prepared' => [
                'name' => 'Demo Product',
                'product_number' => 'demo-001',
                'language' => 'en',
                'locale' => 'en',
                'master_product_number' => 'demo-001',
                'brand' => 'PSI Demo',
                'description' => 'This is a demo product',
                'tags' => 'demo, promotion',
                'ean_code' => '4006381333931',
                'product_groups' => ['05138008', '08094001'],
                'certificates' => ['CERT-04200000'],
                'colors' => ['CG-BLAK5'],
                'color_description' => 'Black',
                'country_origin' => 'CC-DE',
                'made_in' => 'CC-DE',
                'images' => [0],
                'delivery_time_max' => 3,
                'delivery_time_min' => 1,
                'finishings' => [1],
                'finishings_information' => 'Screen printing available.',
                'legal_information' => 'Not suitable for children under 3.',
                'material_description' => 'Acrylic',
                'materials' => ['MG-ACRC7'],
                'measurement_length' => 100,
                'measurement_volume' => 10,
                'measurement_height' => 150,
                'measurement_width' => 135,
                'measurement_information' => 'Dimensions in millimetres.',
                'weight_netto' => 10,
                'weight_brutto' => 13,
                'minimum_order_amount' => 1,
                'packaging' => 2,
                'price_ranges' => [2],
                'price_ranges_information' => 'Prices in EUR, excluding VAT.',
                'product_information' => 'Reusable acrylic promotional product.',
                'stock_available' => true,
                'delivery_information' => 'Ships within 3 business days.',
                'target_group' => 'Adults',
                'video' => 'https://example.com/demo-product.mp4',
            ],
            'mask' => [
                'images' => [true],
                'finishings' => [true],
                'price_ranges' => [true],
            ],
            'properties' => [
                'stdClass' => [
                    'src' => ['https://psiproductfinder.de/images/logo/logo.svg'],
                    'name' => ['Demo product image'],
                    'description' => ['Front view of the product', 'Demo application'],
                    'group' => [1 => 'FG-APPN11'],
                    'included' => [1 => false],
                    'amount' => [2 => 1],
                    'price_ek' => [2 => 1.5],
                    'price_uvp' => [2 => 2],
                ],
            ],
        ]),
    ]
);
$body = $response->getBody();
print_r(json_decode((string) $body));