Twitter API token request returning gobbledygook - php

Question

I'm trying to use Application Only Authentication, as described here:
https://developer.twitter.com/en/docs/basics/authentication/overview/application-only
I'm using the following PHP code to do so.
if(empty($_COOKIE['twitter_auth'])) {
require '../../social_audit_config/twitter_config.php';
$encoded_key = urlencode($api_key);
$encoded_secret = urlencode($api_secret);
$credentials = $encoded_key.":".$encoded_secret;
$encoded_credentials = base64_encode($credentials);
$request_headers = array(
'Host: api.twitter.com',
'User-Agent: BF Sharing Report',
'Authorization: Basic '.$encoded_credentials,
'Content-Type: application/x-www-form-urlencoded;charset=UTF-8',
'Content-Length: 29',
'Accept-Encoding: gzip'
);
print_r($request_headers);
$ch = curl_init();
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_HTTPHEADER, $request_headers);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_URL, 'https://api.twitter.com/oauth2/token');
curl_setopt($ch, CURLOPT_POSTFIELDS, 'grant_type=client_credentials');
$attempt_auth = curl_exec($ch);
print_r($attempt_auth);
}
It should return JSON with the token in it, but instead it returns gobbledygook, as seen in the image below:
I'm sure I'm missing some very simple step, where am I going wrong?
If I send the curl request without the headers, it returns an error in JSON format as expected, so is there something wrong with my headers?

Answer 1

You have few options here. Instead of setting header directly, use below
curl_setopt($ch, CURLOPT_ENCODING, 'gzip');
If you set header directly then you should use
print_r(gzdecode($attempt_auth));
See below thread as well
Decode gzipped web page retrieved via cURL in PHP
php - Get compressed contents using cURL