Use ddclient with changeip.com
This is my most recent working config for ddclient and ChangeIP (Debian 9)
#ddclient.conf
#tell ddclient how to get your ip address
use=web, web=ip.changeip.com
#provide server and login details
protocol=changeip
ssl=yes
server=nic.changeip.com/nic/update
login=yourLogin
password=yourPassword
#specify the domain(s) to update
your.domain.name [, your.domain2.name] [, ...]