[northlandboy]

I think the command you want is this one:

add interface eth3c0 address 192.168.1.2/24

Read the CLI guide.

Clish is good, but you need to spend some time learning how it works.

If you can't/won't use clish, then when you do an install, on first bootup it asks you if you want to put an IP address on an interface. Do that, then do the rest with Voyager through a client web browser.