How do I make a reverse proxy with nginx on my dockerized express server? - express

Question

I currently have two docker containers:
- Frontend, which is ran with the flag -p 80:3000 to map my react app to my domain to serve the content
- Backend, which is ran with the flag -p 3001:3001 to map my backend(nodejs/express) to port 3001, where i will access the API routes
When my backend container is running, I can, for example, run curl localhost:3001/example and it will GET the api response back.
My problem is that I have just set up CloudFlare for my domain, so I now have HTTPS enabled, which Express does not support right out of the box (I also tried createServer with https, it didn't work). After doing some research, I discovered that I should be making a reverse proxy with nginx to have those HTTPS requests work with my HTTP server. Is this possible? Currently my backend won't work on my deployed website when I access the HTTPS routes and try to call to it. How do I go about setting up the reverse proxy to allow the HTTPS requests to go into HTTP ? Should I be somehow getting SSL certificate information and putting it somewhere as well? I've been trying to look up tutorials online, but none seem to address something like this from what I could find. Additionally, I found someone on SO that was having a similar problem, but it was never solved. here
For reference, here's a snippet of my backend if that's useful:
const express = require("express");
const webserver = express();
const cors = require("cors");
const mysql = require("mysql");
//connection pool creation
..
webserver.use(cors());
webserver.use(express.json());
// api routes
..
webserver.listen(PORT, () => {
console.log(`[Express] Server running on ${PORT}`);
});