php+curl to send a post request with fields - php

Question

trying to send post request to api, to get an image back.
example url:
https://providers.cloudsoftphone.com/lib/prettyqr/createQR.php?user=1003123&format=png&cloudid=asdasdasd&pass=123123123
the above url works fine in the browser,
the api doesnt care if the request is get/post,
result of my code is always 'invalid input'.
code:
$url='https://providers.cloudsoftphone.com/lib/prettyqr/createQR.php';
$u = rand();
$p = rand();
$fields = array(
'user'=> urlencode($u),
'pass'=> urlencode($p),
'format'=> urlencode('jpg'),
'cloudid' => urlencode('test')
);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
$output = curl_exec($ch);
curl_close($ch);
echo $output;
on a side note: is there a way to debug the request in order to see what is being sent ?

Answer 1

The URL provided isn't working for POST request. Here is resulting screenshot (I tried using Advance Rest Client)
However Its working perfectly with GET method. So you can continue using GET request method to generate QR code.
I agree that GET isn't much secure compare to POST method but in your case while requesting from curl user won't get to know about such URL parameters (userid, password). Because curl request will be sending from your web server and not from client/user's browser.
Later you can just output the response image you got from the api.