Paynamics laravel软件包不起作用。（laravel 5.8）

Question

我已经安装了paynamics / paygate-sdk-php laravel软件包。向Paygate / paynamics发送请求时出错。示例代码：

$client = new \CoreProc\Paynamic`enter code here`s\Paygate\Client([
            'merchant_id'     =>  env('PAYGATE_MERCHANT_ID', null),
            'merchant_key'    =>  env('PAYGATE_MERCHANT_KEY', null),
            'sandbox'         => false,
            'sandbox_url'     => env('PAYGATE_SANDBOX_URL', null),
            'production_url'  => 'PRODUCTION URL',
            'verify' => false
        ]);
        $requestBody = new \CoreProc\Paynamics\Paygate\RequestBody([
            'request_id' => substr(uniqid(), 1, 13),
            'fname' => 'Paynamics',
            'mname' => 'Paynamics',
            'lname' => 'Buyer',
            'address1' => '101 Oval St.',
            'address2' => '101 Oval St.',
            'city' => 'Pasig City',
            'state' => 'Metro Manila',
            'country' => 'PH',
            'zip' => '1600',
            // 'amount' => 100,
            'email' => 'abcd@gmail.com',
            'phone' => '+63 123 8745',
            'secure3d' => '+63 987 123 4587',
            'currency' => 'PHP',
            'descriptor_note' => 'PayGate Sample Merchant',
            'notification_url' => 'http://example.com/notify',
            'response_url' => 'http://example.com/success',
            'cancel_url' => 'http://example.com/cancel',
            'mtac_url' => 'http://example.com/tnc',
            'mlogo_url' => 'http://example.com/assets/logo.png',
        ]);
        $items = new \CoreProc\Paynamics\Paygate\ItemGroup;
        $items->amount = 100;
        $requestBody->setItemGroup($items);
        $client->send($requestBody);
        // Paygate
        // $client->responsivePayment($requestBody);

我出错了。 "Interface 'Coreproc\Paynamics\Paygate\Contracts\ResponseInterface' not found"