Range extending using TD-W8970 connected via TL-PA4010 / TL-WPA4220
I have a W8970 which I wish to use as an access point to extend my home network because it has external antenna connections and I need to use a wall-mounted external antenna already installed at the rear of the house to get a signal above a summerhouse in the garden.
The primary router is at the front of the use and not in range of the W8970 but I have successfully extended that using a powerline pair of a PA4010 and WPA4220.
The WPA4220 and W8970 will be adjacent so I could use a direct wired connection from the WPA4220 into the W8970 WAN port but I have seen a previous post that says that this is not supported by the W8970.
Can someone please point me at some instructions for setting that up if it is possible, I have tried W8970 to dynamic IP fails to get a lease and setting a fixed address produces a message saying the WAN and LAN can't have the same subnet.
Failing that, if the W8970 doesn't support the wired approach, are there instructions for setting up WDS using the WPA4220 as the source. I have found something along those lines here but they refer to a more modern family of devices and the functions listed don't appear in the W8970 setup pages:
https://www.tp-link.com/uk/support/faq/227/