Fehler in Api-Antwort:
array(4) {
  ["url"]=>
  string(54) "https://api.spar-mit.com/public/api/check_redirect_url"
  ["error"]=>
  string(42) "Resolving timed out after 508 milliseconds"
  ["errno"]=>
  int(28)
  ["http_status"]=>
  int(0)
}
Response:

Curl_response Object ( [url] => https://api.spar-mit.com/public/api/check_redirect_url [http_status] => 0 [error_no] => 28 [error_msg] => Resolving timed out after 508 milliseconds [cache_info] => [decoded:Curl_response:private] => [plain_response:Curl_response:private] => )