Running socket.io on A2hosting VPS hosting - socket.io

Question

A2hosting seems not pass socket = io("https://localhost:45678") to the server.
I have done the following and check below article but still can't figure out.
Running socket.io on Shared Hosting
ssh into the server
go to /public_html directory
npm install socket.io and go to node_modules directory
edit server.js below and node server.js
const { createServer } = require("http");
const { Server } = require("socket.io");
const httpServer = createServer();
const io = new Server(httpServer, { cors: {
origin: '*',
} });
io.on("connection", (socket) => {
console.log("connection")
});
httpServer.listen(45678);
5. revise the .htaccess file in the public_html directory with
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
RewriteRule ^$ http://127.0.0.1:45678/ [P,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ http://127.0.0.1:45678/$1 [P,L]
</IfModule>
6. from the client side, just create php file and excute below
const socket = io("https://localhost:45678");
but the console said "Failed to load resource", it seems the request do not go to server.
7. if item 6 is changed to socket = io("https://muazkhan.com:9001/") it is ok.
I have ask A2hosting but they can check the port is open but not able to fix the problem.
Please help me. Thanks a lot.