You can do this way also.
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,"http://www.abctest.com/abc.php");
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS,$vars); //Post Fields
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
//********************Check these lines for headers*******************
$headers = [
'Content-Type: application/x-www-form-urlencoded; charset=utf-8',
'x-access-token':'sdsdgdsggrtyrtghf'
];
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
// ************************ END Заголовки ******************* **************
$server_output = curl_exec ($ch);
curl_close ($ch);
print $server_output ;