The guest access of the FRITZ!Powerline adapter can only be used with a FRITZ!Box.

In a FRITZ!Box home network, the guest access of the FRITZ!Powerline adapter can provide an additional guest network. The guest access cannot be used with routers from other manufacturers.

If your router has its own guest access function, you can use the FRITZ!Powerline adapter to increase the range of that guest network. To do so, connect the FRITZ!Powerline adapter with the router's guest network. Note that in this case, the FRITZ!Powerline adapter only extends the router's guest network and not the router's conventional Wi-Fi network.