@user51462 Lol it's been not yet 2 weeks and there is yet another user who downvoted my post despite having a very poor understanding of the mathematics involved.
I'm developing a website with react.js. And backend are node.js and express.
Now all of programs are run in local, frontend run on port 3000, backend on port 8080, and everything going well.
But when I trying to use ngrok to build them up and call backend api via ngrok url, then I got a confuse t...