The reverse proxy is th single system because it tells the incoming traffic where to go. It also doesn’t really do anything unless the incoming traffic is requesting one of the domains you set up. it doesn’t affect your internal DNS. You are able to redirect from the public address to your internal server through DNS though.
nginx proxy manager
At a high level you forward ports 80 and 443 to NPM from your router. In NPM you set up your proxy by IP address and port and you can also set up automatic SSL certs when you create the proxy via letsencrypt. I also run a DDNS auto update that tells porkbun if my IP changes. I’d be happy to get into some more specifics if there’s a particular spot you’re stuck. This is all assuming you have a public IPv4 and aren’t behind cgnat. If you have cgnat you’re not totally fucked but it makes it more complicated. If it’s OPNsense related struggles that shit is mysterious to me, I’ve only been running it a few weeks and it’s not fully configured. Still learning.
I use nginx proxy manager and let’s encrypt with a porkbun domain, was very easy to set up for me. Never tried caddy/traefik/etc though. Geo blocking happens on my OPNsense with the built in tools.
Mine works but I’m not in a position to confirm what my yaml looks like, I’ll try to remember to check before work.