PHP cURL GET request and request's body

i'm trying using cURL for a GET request like this:

function connect($id_user){
    $ch = curl_init();
    $headers = array(
    'Accept: application/json',
    'Content-Type: application/json',

	);
    curl_setopt($ch, CURLOPT_URL, $this->service_url.'user/'.$id_user);
 	curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    $body = '{}';

    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET"); 
    curl_setopt($ch, CURLOPT_POSTFIELDS,$body);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
 
    // Timeout in seconds
    curl_setopt($ch, CURLOPT_TIMEOUT, 30);
 
    $authToken = curl_exec($ch);
 
    return $authToken;
}

As you an see i want to pass $body as the request's body , but i don't know if its correct or not and i can't debug this actually, do you know if is the right to use curl_setopt($ch, CURLOPT_POSTFIELDS,$body); with a GET request?

Cause this enteire code works perfect with POST, now i'm trying change this to GET as you can see

The accepted answer is wrong. GET requests can indeed contain a body. This is the solution implemented by WordPress, as an example:

curl_setopt( $ch, CURLOPT_CUSTOMREQUEST, 'GET' );
curl_setopt( $ch, CURLOPT_POSTFIELDS, $body );

EDIT: To clarify, the initial curl_setopt is necessary in this instance, because libcurl will default the HTTP method to POST when using CURLOPT_POSTFIELDS (see documentation).

CURLOPT_POSTFIELDS as the name suggests, is for the body (payload) of a POST request. For GET requests, the payload is part of the URL in the form of a query string.

In your case, you need to construct the URL with the arguments you need to send (if any), and remove the other options to cURL.

curl_setopt($ch, CURLOPT_URL, $this->service_url.'user/'.$id_user);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_HEADER, 0);

//$body = '{}';
//curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET"); 
//curl_setopt($ch, CURLOPT_POSTFIELDS,$body);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

  <?php
  $post = ['batch_id'=> "2"];
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL,'https://example.com/student_list.php');
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post));
  $response = curl_exec($ch);
  $result = json_decode($response);
  curl_close($ch); // Close the connection
  $new=   $result->status;
  if( $new =="1")
  {
    echo "<script>alert('Student list')</script>";
  }
  else 
  {
    echo "<script>alert('Not Removed')</script>";
  }
   
  ?>

For those coming to this with similar problems, this request library allows you to make external http requests seemlessly within your php application. Simplified GET, POST, PATCH, DELETE and PUT requests.

A sample request would be as below

use Libraries\Request;

$data = [
  'samplekey' => 'value',
  'otherkey' => 'othervalue'
];

$headers = [
  'Content-Type' => 'application/json',
  'Content-Length' => sizeof($data)
];

$response = Request::post('https://example.com', $data, $headers);
// the $response variable contains response from the request

Documentation for the same can be found in the project's README.md

you have done it the correct way using

curl_setopt($ch, CURLOPT_POSTFIELDS,$body);

but i notice your missing

curl_setopt($ch, CURLOPT_POST,1);