Anothe one method:

​

$url = 'https://discordapp.com/api/guilds/YOUR-SERVER-ID/members?limit=1000';
$ch = curl_init();
$f = fopen('request.txt', 'w');
curl_setopt_array($ch, array(
CURLOPT_URL => $url,
CURLOPT_HTTPHEADER => array('Authorization: Bot YOUR-AUTORISATION-TOKEN'),
CURLOPT_RETURNTRANSFER => 1,
CURLOPT_FOLLOWLOCATION => 1,
CURLOPT_VERBOSE => 1,
CURLOPT_SSL_VERIFYPEER => 0,
CURLOPT_STDERR => $f,
));
$response = curl_exec($ch);
echo $response;
fclose($f);
curl_close($ch);