AppTokenPhpExample.php errors

[smokey18]

I've used the same code available in the example and just replaced the keys as mentioned at the start.
But when started the server It gave these 2 errors.
My applicant is created without any issue but on addDocument it doesn't create anything.
Anyone have any idea about this issue?

1. Warning: Undefined variable $response in C:\xampp\htdocs\unlimint\app\AppTokenPhpExample.php on line 61

2. Fatal error: Uncaught Error: Call to a member function getBody() on null in C:\xampp\htdocs\unlimint\app\AppTokenPhpExample.php:61 Stack trace: #0 C:\xampp\htdocs\unlimint\app\AppTokenPhpExample.php(92): App\AppTokenGuzzlePhpExample->sendHttpRequest(Object(GuzzleHttp\Psr7\Request), '/resources/appl...') PHP: Fix stream offset before the send #1 C:\xampp\htdocs\unlimint\app\AppTokenPhpExample.php(134): App\AppTokenGuzzlePhpExample->addDocument('id...') PHP: Simplify UNIX time generation #2 {main} thrown in C:\xampp\htdocs\unlimint\app\AppTokenPhpExample.php on line 61