Ustream API basic usage:
--------------------------
----- Authentication --------
--------------------------
<br />
<b>Fatal error</b>:  Uncaught GuzzleHttp\Exception\ClientException: Client error: `POST https://www.ustream.tv/oauth2/token` resulted in a `400 Bad Request` response:
{&quot;error&quot;:&quot;invalid_request&quot;,&quot;error_description&quot;:&quot;Header parameter client_secret missing&quot;}
 in /home/fortmdev/fort29.mdev.pl/public_html/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php:113
Stack trace:
#0 /home/fortmdev/fort29.mdev.pl/public_html/vendor/guzzlehttp/guzzle/src/Middleware.php(66): GuzzleHttp\Exception\RequestException::create()
#1 /home/fortmdev/fort29.mdev.pl/public_html/vendor/guzzlehttp/promises/src/Promise.php(203): GuzzleHttp\Middleware::GuzzleHttp\{closure}()
#2 /home/fortmdev/fort29.mdev.pl/public_html/vendor/guzzlehttp/promises/src/Promise.php(156): GuzzleHttp\Promise\Promise::callHandler()
#3 /home/fortmdev/fort29.mdev.pl/public_html/vendor/guzzlehttp/promises/src/TaskQueue.php(47): GuzzleHttp\Promise\Promise::GuzzleHttp\Promise\{closure}()
#4 /home/fortmdev/fort29.mdev.pl/public_html/vendor/guzzlehttp/promises/src/Promise.php(246):  in <b>/home/fortmdev/fort29.mdev.pl/public_html/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php</b> on line <b>113</b><br />