使用PHP Curl向Paste.ee API提交新粘贴不起作用

I'm trying to submit a new paste to Paste.ee API using Curl, but the response is always Whoops, looks like something went wrong.

Here's the guideline of Paste.ee API: https://paste.ee/wiki/API:Basics

Here's how my simple code looks like:

<?php 
$key = '56b3f127d65445c0cf6ff05f62ffba53';
$format = 'JSON';
$description = 'just for testing';
$paste = 'Just a simple test';

        if(function_exists('curl_init')) {
            $ch = curl_init(); 
            curl_setopt($ch, CURLOPT_URL, "http://paste.ee/api");
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
            curl_setopt($ch, CURLOPT_POST, true); 
            curl_setopt($ch, CURLOPT_HTTPHEADER, array("Expect:")); 
            curl_setopt($ch, CURLOPT_HEADER, false); 
            curl_setopt($ch, CURLOPT_POSTFIELDS, array("key" => $key, "format" => $format, "description" => $description, "paste" => $paste)); 
            
            $response = curl_exec($ch);
            curl_close($ch);
            echo $response;

        } else {
            error_log("You need cURL to use this api!");
        }
?>

I've double-checked, my key is right. I'm new to Curl, so any advice would be very appreciated. Thanks.

</div>

It's because "format" is case sensitive in which it must small letters

You your format is capitalised which is it should be small letters

"format": "json"

look

$key = '56b3f127d65445c0cf6ff05f62ffba53';
$format = 'JSON';
$description = 'just for testing';
$paste = 'Just a simple test';
$ch = curl_init(); 

curl_setopt($ch, CURLOPT_URL, "http://paste.ee/api");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
curl_setopt($ch, CURLOPT_POST, true); 
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Expect:")); 
curl_setopt($ch, CURLOPT_HEADER, false); 
curl_setopt($ch, CURLOPT_POSTFIELDS, array(
    'key' => $key,
    'format' => $format,
    'description' => 'just for testing',
    'paste' => $paste,
    'format' => 'json'
    )); 

CAPITALISED WHICH RETURNS ERROR

small letters which returns the correct json data