I use dynu.com…works great
Found this for a windows solution (I guess running on a machine behind the firewall
https://download.cnet.com/Dynu-IP-Update-Client/3000-2381_4-10422952.html
there is ddclient with the “other” option as well
https://www.dynu.com/FAQ/Dynamic-DNS-Service#IPUpdate
As Joulinar said, ddclient is the fastest/easiest way to get it going