Forgot to set netgate during installation

I am using a wireless connection, but forget to set the netgate during the installation.
Now I can ping my router, but have no access for the Internet.
I tried to set the netgate in YaST-system-network settings-route , however, when I click next after input my router’s IP, it prompts that a package named IW needed to be installed.
OMG…I am not able to connect to the outside world yet, how can I install it from downloading?

Is there a way I can input the netgate manually in a .conf file?

Are you using Network Manager or wicked to manage network? Any reason you do not use DHCP that would most likely assign correct default route?

Edited the gateway and dns manually, now I am able to use opensuse to replay this thread.
Problem solved!