@dvdprsn 

Hello, 

How many powerline devices you have in total, only this WPA8630 or there is a kit? What's the status of the lights of these 2 units?

If you only have one WPA8630 extender, you will need to connect it to your host router with an ethernet cable in order to transfer internet to this extender network.

But if you have two and there is no internet access, please press and hold the pair button for more than 6 seconds to reset the powerline adapter to factory defaults. Then repair them with the below instruction and give it a go.
https://www.tp-link.com/faq-258.html