Исключение мыла DPDAppService

Question

Я застрял в реализации DPDAppService: Ошибка: неустранимая ошибка: необработанное исключение SoapFault: [S:Server] pl.com.dpd.umlf.exceptions.UMLFException: org.xml.sax.SAXParseException: содержимое не допускается в прологе.

Вот мой код:

function testDPDAPP () {

 $client = new \SoapClient('https://dpdappservicesdemo.dpd.com.pl/DPDCRXmlServicesService/DPDCRXmlServices?wsdl', [
        'cache_wsdl' => false,
        'trace' => true,
    ]);
 $auth = [
        'login' => 'DAStest',
        'masterFid' => '1495',
        'password' => '123_DAStest_456'
    ];


    $paramsPackages = [
            'Packages' => [
                'Package' => [
                    'Sender' => [
                        'Company' => 'a',
                        'Name' => 'przesylka z app services',
                        'Address' => 'Carska 32',
                        'City' => 'Warszawa',
                        'CountryCode' => 'PL',
                        'PostalCode' => '02272',
                        'Phone' => '9999999',
                        'Email' => '[e-mail]'
                    ], 'Receiver' => [
                        'Company' => 'a',
                        'Name' => 'przesylka z app services',
                        'Address' => 'Terencjusza 12',
                        'City' => 'Olsztyn',
                        'CountryCode' => 'PL',
                        'PostalCode' => '10178',
                        'Phone' => '999999',
                        'Email' => '[e-mail]'
                    ], 
                    'PayerType' => 'SENDER',
                    'Ref1' => '',
                    'Ref2' => '',
                    'Customer' => [
                        'FID' => '1495'
                    ],
                    'Services' => [
                    ], 'Parcels' => [
                        'Parcel' => [
                            'Weight' => '35',
                            'SizeX' => '100',
                            'SizeY' => '40',
                            'SizeZ' => '40',
                            'Content' => 'teest',
                            'CustomerData1' => 'raz 2',
                            'CustomerData2' => 'raz 2',
                            'CustomerData3' => 'raz 2',
                        ]
                    ]
                ]
            ]

        ];
          $req = [
            'openUMLFXV2' => base64_encode(json_encode($paramsPackages)),
            'authDataV1'  => $auth

        ];


        $client->importPackagesXV1($req);

}

Что я делаю не так?