@tmomas thanks a lot. I have learnt my lesson, the hard way. I cannot now get the router to accept an external IP from my router that is connected to the Internet, which I need to install luci. I still can however connect to its 192.168.1.1 address. Any further help would be great.
And I am very happy with this version. It's beautiful. I'm only wondering now (1) when the release is official how different that might be from what I have now (2) would upgrading simply involve downloading the sysupgrade file and then flashing with luci, now that I have luci with the current: openwrt-22.03.0-rc1-lantiq-xrx200-avm............
Thanks a lot for now anyway!