Problem getting post data in API via php curl call - php

Question

I am trying to send a file to a slim API via curl PHP.
Actually I have a PHP file that receive a from post data and is suppose to call a slim API with the received data and slim API is going to store the data in the database. It works fine when there is no file in the data but when I send a file to API along with other data using PHP curl and set the 'content-type: multipart/form-data' I miss all the posted data in API side. I couldn't figure out what's wrong with it!!!
By the way it works well when I test the API with postman. The API successfully gets the file and save it in the storage. The problem must be in the client side where I call the API using curl and PHP.
Could anybody please help me how to setup the curl call to to make the API work ?
Thanks a lot
route.php
$app->post('/softwareskills/insert', SoftwareSkillsController::class . ':insert')->setName('SoftwareSkills.insert');
SoftwareSkillsController.php
class SoftwareSkillsController {
public function insert(Request $request, Response $response, array $args)
{
$params= $request->getParsedBody();
$file = $request->getUploadedFiles();
var_dump($params); // return empty array!
var_dump($file); // return empty array!
}
}
upload.php
<?php
// $_POST and $_FILES to send them via php CURL
$tmpfile = $_FILES['attachment']['tmp_name'];
$filename = basename($_FILES['attachment']['name']);
$filemime = $_FILES['attachment']['type'];
$data = array(
"StNo" => $_POST['StNo'],
"SoftwareName" => $_POST['SoftwareName'],
"proficiency" => $_POST['proficiency'],
"attachment" => new CURLFile($tmpfile,$filemime,$filename)
);
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => "http://myapi.com/softwareskills/insert",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => http_build_query($data),
CURLOPT_HTTPHEADER => array(
"content-type: multipart/form-data"
),
));
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}