Proxy server failing when attempting to access over HTTPS

[eat-sleep-code]

I am trying to setup a proxy server to pass requests made to one server, to another. I am having a bit of trouble getting this to work on HTTPS.

The server is a VM running Windows Server 2019.

This is my program:

    const fs = require('fs');
    const express = require('express');
    const morgan = require('morgan');
    const { createProxyMiddleware } = require('http-proxy-middleware');
    
    const Host = '0.0.0.0';
    const Port = 3000;
    const TargetBaseURL = 'https://myaddressgoeshere.com/';
    
    const sslKey = fs.readFileSync('ssl/key.pem', 'utf8');
    const sslCert = fs.readFileSync('ssl/cert.pem', 'utf8');
    
    const app = express();
    
    app.use(morgan('dev'));
    
    app.use('/proxy', createProxyMiddleware({
    	target: TargetBaseURL,
    	changeOrigin: true,
    	pathRewrite: {
    		[`^/proxy`]: '',
    	},
    	protocol: 'https:',
    	secure: true,
    	ssl: {
    		key: sslKey,
    		cert: sslCert
    	}
    }));
    
    
    app.listen(Port, Host, () => {
    	console.log(`Starting Proxy at ${Host}:${Port}`);
    });

I created an self-signed cert by executing the following lines at the Command Prompt:

    C:
    cd "C:\Program Files\Git\usr\bin"
    openssl genrsa -out cert.key 2048
    openssl req -new -key cert.key -out cert.csr
    openssl x509 -req -days 3650 -in cert.csr -signkey cert.key -out cert.crt
    openssl x509 -in cert.crt -out cert.pem -outform PEM
    openssl rsa -in cert.key -text > key.pem

I copied the files that the above steps created to my projects /ssl folder.

When I make a request to http://proxyaddress:3000/proxy/login , it loads but ultimately fails due to the proxied target's CSP wanting https://

When I make a request to https://proxyaddress:3000/proxy/login the program never loads, no request gets written to the console from via the morgan middleware, and Chrome displays a good old:

ERR_SSL_PROTOCOL_ERROR

When I run curl, I get...

curl: (35) LibreSSL/3.3.6: error:1404B42E:SSL routines:ST_CONNECT:tlsv1 alert protocol version

Can anyone point me in the direction of what I might be able to do to get this working?