(Provided you really do have a static IP, with DSL or cable connections you get a dynamic IP (either every day or with a reconnect). Then you'd need to look up something called "Dynamic DNS".)
Then you need to forward some ports to your local machine, that is done in your router. Usually you can map any external port to any internal port, so you would just route all traffic that comes in on e.g. port 8000 to your local machine on port 80. (On a sidenote: what ISP blocks ports 80 and 443, lol? I'd switch ISP if possible).
But your choice of internal ports don't really matter, because that's job is better left to the reverse proxy. I'd suggest "Nginx Proxy Manager", which is a nginx proxy with a very nice GUI that comes as a docker. It makes routing ports and especially obtaining SSL certificates a breeze. I find that way more accessible than traefic or caddy or basic nginx. You'll find lots of tutorials for this.
So to recap: connect IP to URL with a DNS record at the domain registrar, forward some ports in your router, which ones doesn't really matter because you can just "bend" them anyway you like with the reverse proxy.