It depends on what all you want to proxy in, if it’s just that one thing then it’s pretty simple to point a port inbound to a secure interface and call it a day.
For a more complete thing, an inbound proxy will take the requested domain coming into your front door and translate it to an IP/port combo on the inside. That way you can have several services behind the single IP. If you have a full gateway server setup in frontt of things something like HAProxy or squid can work and do SSL offloading for you. For a single server setup you might look at ‘nginx proxy manager’ (NPM) which gives an easy way to set up an inbound proxy plus it’ll manage getting certificates from let’s encrypt automatically.
I could help more fully but need a good bit more details to give some specific ideas.