api connection

[Tempusr6]

hello guys, id like to integrate our chevereto instance in our forum.
the pup upload plugin doesnt work very well (for the small button integration in the editor - see McAtzes thread for details).
id like to have the following:

customizing the original button or adding a hardcoded button instead of sibling-method.
clicking on it will trigger the same popup as the original button, or directly the file-browser-window:


when a file is chosen, it is uploaded to the chevereto instance.
it would be great if the image is inserted dynamic like in the original uploader


but i would also be happy if only the bb-embed-code would be inserted.

how can i achieve this? can somebody point me in the right direction?
is this something to begin with or am i completely wrong?

$requestData = [
    'key' => 123456789,
    'source' => 'file',
    'format' => 'redirect'
];

$jsonData = json_encode($jsonData);

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => "http://cheveretoURL/api/1/upload",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => $jsonData,
  CURLOPT_HTTPHEADER => array(
    "Content-Type: application/json"
  ),
));

$response = curl_exec($curl);

curl_close($curl);
echo $response;

thanks :-*