public void enviarMensaje(String url, String mensaje) {

    new BukkitRunnable() {
        @Override
        public void run() {
            try {
                URL webhook = new URL(url);
                HttpURLConnection connection = (HttpURLConnection) webhook.openConnection();
                connection.setRequestMethod("POST");
                connection.setRequestProperty("Content-Type", "application/json");
                connection.setDoOutput(true);

                String json = "{\"content\": \"" + mensaje + "\"}";

                try (OutputStream os = connection.getOutputStream()) {
                    os.write(json.getBytes());
                }
                connection.getInputStream();
            } catch (Exception e) { e.printStackTrace(); }
        }
    }.runTaskAsynchronously(plugin);
}