403 error rest_'cookie_invalid_nonce' on API Request

I'm currently developing a Plugin in which I'm in need of retrieving information from a third-party plugin API.

To authenticate my users, I am trying to use the vanilla authentication via cookie as explained in the official documentation, but every request is refused with a 403 rest_cookie_invalid_nonce code.

I cannot understand what I'm doing wrong.

My code:

function makeRequest(){
  $url = 'https://xxxxxx.com.br/wp-json/wcfmmp/v1/orders/';
  $nonce = wp_create_nonce('wp_rest');
  $curl = curl_init();
  curl_setopt($curl, CURLOPT_URL, $url);
  curl_setopt($curl, CURLOPT_HTTPHEADER, array(
    'X-WP-Nonce:'. $nonce,
    'Content-Type: application/json',
  ));
  $result = curl_exec($curl);
  if(!$result) {
    die(Connection Failure);
  }
  curl_close($curl);
  return $result + var_dump($nonce);
}