Invalid Token time

I’m using samsung web service app and trying to get a valid token for a period of time through this api
but, I’m getting invalid expiry time . So, please provide me a better way to solve this issue.

here, Is the request for getting token.

Request: (’.$code.’&client_id=’.$client_id.’&client_secret=’.$client_secret.’&redirect_uri=’.urlencode($redirect_url)) ( .
requested time is 1532425476

Response: [expiry_time] => 1529452800
[value] => 4fc4f545-70d2-4a5e-81f6-26c673f6e7ba.