HTTP Requests removed on Android Pie (API 28+)

Hello, i have an app which needs HTTP requests to my server to work, and it works fine on every device(iOS and Android) except Android 9.0 Pie (API 28+), and i can't get it to work. After some research i found that Google had removed HTTP connections by default on Android Pie due to unencrypted and security reasons, but there is a way to set it only for my domain, but to do that requires to edit the manifest file, and to add an extra XML file, but i have no clue how to do it on Unity. Im using the latest stable version of Unity 2018.3.5f1. Here is the default code i use for HTTP requests :

  IEnumerator UpdateCheck() // Get updates
     {
         using (WWW www = new WWW("http://example.com/update.php?"))
         {
             yield return www;
            print(www.text);
     }
 }

Thanks!