PPPoE mode is not working in TP Link CPE210

Installed OpenWRT in my TP-Link CEP 210 Outdoor Wireless Communication device. It successfully installed. When i tried to change network interface mode from Static Address to PPPoE and then waited for 90 seconds, it rolls back the changes.

I tried installing older versions but the same problem occured on versions 19.04, 19.10 and 21.4 and 22.04

How to configure my device as an access point with PPPoE on OpwnWrt.

Does it have one or two ports?

in which component, router or cpe210?
if it is the router, it has 4+1 ports

You are trying to make it work on cpe210, so the cpe210.

CPE 210, one port on the outdoor device and lan, poe in a PoE injector.

Then it is expected that you are losing connectivity. First you connect to the wifi. Then you need to separate the ethernet port from the lan interface, so only the wifi will belong to the lan. Afterwards you can change the ethernet port to pppoe-wan.