Dynamic updates. So long as you're not behind carrier NAT you can find your IP number and update a DNS record. Many DNS providers have a specific service for this, e.g. https://dyn.com/dynamic-dns/ (no affiliation, just used them many years ago for this service).
Many ISPs are switching to carrier NAT though and then you can't host as you don't have a routable IP number.
Many ISPs are switching to carrier NAT though and then you can't host as you don't have a routable IP number.