converts to PHP corresponds to the following code

<?php

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => "http://af.epicc.com.cn/api/misc/creditEntry/creditInfoSubmit",
  CURLOPT_RETURNTRANSFER => true,
  //  --compressed
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => "------WebKitFormBoundary0vi094pNr9jxqbUH\r\nContent-Disposition: form-data; name=\"saveFlag\"\r\n\r\nsave\r\n------WebKitFormBoundary0vi094pNr9jxqbUH--",
  CURLOPT_HTTPHEADER => array(
    "Cookie: test",
    "Origin: http://af.epicc.com.cn",
    "Accept-Encoding: gzip, deflate",
    "X-Requested-With: XMLHttpRequest",
    "Accept-Language: zh-CN,zh;q=0.9",
    "Authorization: Arch6WithCloud null",
    "Content-Type: multipart/form-data; boundary=----WebKitFormBoundary0vi094pNr9jxqbUH",
    "Accept: application/json, text/javascript, /; q=0.01",
    "Referer: http://af.epicc.com.cn/",
    "jwtToken: test2",
    "Connection: keep-alive",
    "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36"
  ),
));

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error -sharp:" . $err;
} else {
  echo $response;
}

what is the $sign in the red area of the picture? I feel that the effect of this $is not reflected in my code