ubuntu@ubuntu:~$ /usr/local/bin/noip2
Configuration data '/usr/local/etc/no-ip2.conf' is read-only!
No updates can be made.
One noip2 process is already active,
and the multiple instance flag (-M) is not set
Run this command with sudo (or as root). Only root can write to /usr/local/etc/no-ip2.conf.
It also looks like the process is already running (possibly started as service).
you could do the following:
stop the process sudo service stop noip2
manually edit the config sudo nano /usr/local/etc/no-ip2.conf
start the service again sudo service start noip2