(Totally a beginner here)

I want to connect this device to another router to get Wi-Fi access to my room. I know that using a CAT6 cable I can connect it. But the problem is this router has only LAN ports. 

I found this thread How to configure TD-W8960N's LAN port work as WAN port(TD-W8960N work with cable modem) | TP-Link France and I was wondering if I could do the same to this device. The problem is the user interface shown in the thread is no longer here, and I am having quite some difficulties finding the correct settings in the new UI. If you could please explain to me what I can do to convert or any better option, it will be very helpful.