Get Header Authorization value of a login api (sent with username and password in json body) using php curl

PHP Snippet 1:

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, TRUE);
curl_setopt($ch, CURLOPT_POSTFIELDS, $postdata);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch,  CURLOPT_RETURNTRANSFER, 1);


$headers = array(
   "X-Custom-Header: value",
   "X-Custom-Header: value"
);
curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
    

$output = curl_exec($ch); //Call your api at end