why showing this error in{“error”:”invalid_request”,”error_description”:”Missing grant_type parameter value”} in accesstoken creation in rest api

$service_url =’http://mydoubts.in/apspackage/’
$curl = curl_init();
curl_setopt($curl,CURLOPT_HTTPHEADER,array (“Content-Type:application/x-www-form-urlencoded”));

curl_setopt($curl, CURLOPT_POST, 1); // Do a regular HTTP POST

curl_setopt($curl, CURLOPT_POSTFIELDS, ‘client_id=’ . urlencode($client_id) . ‘&’ .
‘client_secret=’ . urlencode($client_secret) . ‘&’ .
‘grant_type=client_credentials’ . ‘&’ .
‘scope=openid’);

curl_setopt($curl, CURLOPT_RETURNTRANSFER, TRUE);
curl_setopt($curl, CURLOPT_FAILONERROR, FALSE);
curl_setopt($curl, CURLOPT_USERAGENT, “Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)”);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($curl, CURLOPT_URL, $service_url);
$response = curl_exec($curl);

print_r($response);

this will work enjoy 🙂