I recently installed OpenSUSE Leap in one old notebook (~2011). During installation a network configuration appeared. I imagined that this type of configuration would be easy with YAST after the system was rolling smooth but so during the install process I skipped the network config window. The problem is that I am not being able to configure DHCP by YAST now with the system configured.
The box that is not available is the YAST// Network Settings // Hostname/DNS -> Change hostname via DHCP.
First you ve to set Netork Setup Method in the Global settings tab to raditional with ifup/wicked. Else YaST assumes you will use NetworkManager and thus not offer any configuration options at all.
Then you must select the network card you want to use DHCP in from the list on the Oveview tab and click Edit below. On the page you will get then, you are able to choose Dynamic ddress using DHCP. Only then is DHCP switched on and only after that you can use the setting you mention above if you think you need that .
While the above may be an answer to your question, I am not sure you are on the correct path. Most notebook users walk around with it and thus connect to different networks very often. This is best done using NetworkManager.
Of course you are the boss and may have reasons to configure with a fixed IP address, etc. and thus prefer Traditional using ifup/wicked. But I hope you took the right decision.