未经授权：从PHP在线访问Web API Dynamics 365

Question

I'm trying to call the Dynamics CRM 365 online using PHP, but I keep getting the same error:

Error: failed with status 401, response HTTP Error 401 - Unauthorized: Access is denied , curl_error

This is my code

define('MS_CRM_URL', 'https://xxxx.crm4.dynamics.com');
define('MS_CRM_USER', '[e-mail]');
define('MS_CRM_PASS', 'xxxxxxxx');
$method = '/api/data/v8.2/contacts';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, MS_CRM_URL . $method);
curl_setopt($ch, CURLOPT_USERPWD, MS_CRM_USER .':'. MS_CRM_PASS);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, array(

));
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);    
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    'Accept' => 'application/json',
    'OData-MaxVersion' => '4.0',
    'OData-Version' => '4.0',
    'Content-Type' => 'application/json',
));

$server_output = curl_exec($ch);
$status_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);

curl_close($ch);

$json = array();
if ((int)$status_code === 200) {
    $json = json_decode($server_output);
}