@enano0 

Hi

Deco only supports Wi-Fi connection between Decos, but cannot connect to non-Deco routers through Wi-Fi. It is recommended that you purchase another Deco, and then you can connect the new Deco to your router via wire, and the Deco X50-PoE can be connected to the main Deco, I mean the new Deco, via Wi-Fi.
Common working topologies for Deco working with routers are as follows:
How to use Deco with your existing router

If you just want one extender, you could consider a range extender:
Range extender