Why does Safari intentionally block websocket requests in converted Chrome extensions to safari extensions?

I am converting chrome extensions to safari extension using Xcode's tool xcrun safari-webextention-converter

after successfully building the conversion and running the extension on safari, I am unable to access the websocket requests...

safari intentionally blocks it . why ?

[Warning] [blocked] The page at https://example.com/ requested insecure content from ws://localhost:8081/. This content was blocked and must (extend.iife_dev.js, line 14)

(function() {let __HMR_ID = "0.psbnbvjdf4g";
const LOCAL_RELOAD_SOCKET_PORT = 8081;
const LOCAL_RELOAD_SOCKET_URL = `ws://localhost:${LOCAL_RELOAD_SOCKET_PORT}`;

const DO_UPDATE = 'do_update';
const DONE_UPDATE = 'done_update';

var MessageInterpreter = {
  send: (message) => JSON.stringify(message),
  receive: (serializedMessage) => JSON.parse(serializedMessage),
};

var initClient = ({ id, onUpdate }) => {
  const ws = new WebSocket(LOCAL_RELOAD_SOCKET_URL);   <----[blocked the ws://localhost:8081 here] 

  ws.onopen = () => {
    ws.addEventListener('message', event => {
      const message = MessageInterpreter.receive(String(event.data));

      if (message.type === DO_UPDATE && message.id === id) {
        onUpdate();
        ws.send(MessageInterpreter.send({ type: DONE_UPDATE }));
      }
    });
  };
};

https://github.com/briehq/brie-extension/issues/172

[Re-Titled by Moderator]

Original Title: [Warning] [blocked] The page at https://example.com/ requested insecure content from ws://localhost:8081/. This content was blocked and must (extend.iife_dev.js, line 14)