How to upload files to an item in php

Am trying to upload files to an item via php by it throws error internal server 500

Please can someone provide me with the right code

Here is my code

$curl = curl_init();
curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://api.monday.com/v2/file',
  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 => array('query' => 'mutation ($file: File!, $item_id: Int!, $column_id: String!) { add_file_to_column ( item_id:$item_id, column_id: $column_id, file: $file) { id}}','variables' => '{"item_id":2267231528, "column_id": "files"}','map' => '{"image":"variables.file"}','image'=> new CURLFILE('https://cdn.pixabay.com/photo/2015/05/26/12/30/baby-784608_960_720.jpg')),
  CURLOPT_HTTPHEADER => array(
    "Authorization: $token"
  ),
));
$response = curl_exec($curl);
curl_close($curl);
echo $response;