I use DuckDNS. There's been only one outage for the ~2 years I've been using it and it's free. I also use DuckDNS to acquire the SSL certificates for the reverse proxy.
If you mean automatically update IP part, duckdns website has a very comprehensive guide.
If you mean getting a free SSL certificate, you can use acme.sh (this is what I used) which has integrated support for duckddns (To use let's encrypt you need to use --server letsencrypt in your command)
I used duckdns for my jellyfin server, but after a week or so I started getting malicious site warnings from Firefox, and had to ‘accept the risk and continue’ every time. Ended up going back to noip. It’s a pain to renew every month, but I haven’t had any other problems with it.
I use noip as well, but because I only have an IP camera on that network, and the camera has built-in DDNS support for noip. But I hate it having to renew monthly.