Sorry, I just re-read my initial post and realise it’s not as clear as I thought.
By “unable to connect”, this is the message shown on the browser page after typing in the URLs as per my initial post.
I powered off the Pi last night, and after switching on this morning, the screen connected to the Pi goes through lots of text and ends as before, “NCP not activated yet. Please enter … etc” and the nextcloudpi login prompt.
The full browser page message is the same today:
“Unable to connect
An error occurred during a connection to .
The site could be temporarily unavailable or too busy. Try again in a few moments.
If you are unable to load any pages, check your computer’s network connection.
If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the web.”
The ip address is in my home network, I am not intending to open it to the internet.
I hope that is clearer.
So, I am unable to load any activation page as shown on How to access NextcloudPi first time & Activation