Question How to make LAN Port can PPPoE in Huawei HG8245H5?

Is this your current network configuration (line diagram)?

ISP === Fiber ===> Huawei Modem/Router [LAN Ports] ----Ethernet cable ----> Wired PCs/devices and ~~~~ wireless ~~~~> PCs/Devices

Feel free to edit and correct the line diagram as necessary.

And you wish to extend the number of wired connections to add more wired devices - correct?

More information needed.