Hello @brainerd，

This EAP can be wired to router or switch to get the internet connection. And EAP will broadcast its own WiFi and extend the WiFi.
Please note that under default settings, EAP's default WiFi will start with TP-Link_xxxx. Please check on different phones.
So the correct physical connection is as follow:
                                  Internet(modem)-----router/switch-------EAP>>><<<<phone/pc

The connection can be:
Please use orginal POE adapter to power EAP.
On PoE adapter, POE port goes to EAP unit while LAN port goes to main router LAN port.

Here is a detailed post to show how to change the EAP's SSID for your reference.