How to up a port

[AEncinas19]

Hello everyone.
I'm in candidate mode and I've created an interface. I've already commit those changes but when I execute the show interface command it appears the following result:
ethernet-1/1 is down, reason lower-layer-down
ethernet-1/1.0 is down, reason port-down
Network-instance:
Encapsulation : null
Type : routed
IPv4 addr : 192.168.255.1/24 (static, None)
I don't know how to port-up. I've seen the Nokia documentation but it doen't appear anything.

Thank you in advance.
Greetings,
Aitor