Nokia G-140W-F - Disabling Wifi only?

Is there a way to "temporarily disable" only the wifi on this router and keep the LAN port working?

Are you going to connect a router through the LAN? If so I would suggest bridge mode
Nonetheless, to disable Wi-Fi login to 192.168.1.1 using admin as username and password

Then Network-->Wireless (2.4Ghz) -->uncheck enable tickbox, do the same for Wireless (5Ghz)

dragonball said:

Is there a way to "temporarily disable" only the wifi on this router and keep the LAN port working?

Click to expand...

i think there will WLAN button at back of device , try pressing once , if doesnt disable , press for 5 seconds and leave , it will disable , repeat same to enable again - No need to login to router to follow this procedure, else you may even set settings in device as well for periodic enabling and disabling of wifi as per schedule set by you.
third option is as said by @Rehan Kumar .