tryed diff values. same issue. here are logs.

Request Headers: array (
0 => 'Content-Type: text/namevalue',
1 => 'X-VPS-Timeout: 45',
2 => 'X-VPS-VIT-Client-Type: PHP/cURL',
3 => 'X-VPS-VIT-Integration-Product: PHP::Zen Cart WPP-NVP',
4 => 'X-VPS-VIT-Integration-Version: 0.1',
)

Request Parameters: array (
'TOKEN' => 'EC-5BB598882X280640N',
'METHOD' => 'GetExpressCheckoutDetails',
'USER' => 'admin_api1.futurewebentertainment.com',
'PWD' => '****************',
'VERSION' => '2.3',
'SIGNATURE' => '****************************************************G-sy',
)

Response: array (
'TIMESTAMP' => '2007-11-22T17:55:02Z',
'CORRELATIONID' => '3a2f2e01295b7',
'ACK' => 'Success',
'VERSION' => '2.300000',
'BUILD' => '1.0006',
'TOKEN' => 'EC-5BB598882X280640N',
'EMAIL' => '[email protected]',
'PAYERID' => '46LA8DSWSTRWY',
'PAYERSTATUS' => 'unverified',
'FIRSTNAME' => 'xxxx',
'LASTNAME' => 'xxxx',
'COUNTRYCODE' => 'GB',
'ADDRESSID' => 'PayPal',
'ADDRESSSTATUS' => 'None',
)

GetExpressCheckoutDetails, Elapsed: 3371ms; Success