Making progress slowly - next problem is that port 443 is already being used by some Plesk processes.
I run sudo lsof -i:443 and get:
nginx 1896 root 19u IPv4 34635 0t0 TCP domain:https (LISTEN)
nginx 1901 nginx 19u IPv4 34635 0t0 TCP domain:https (LISTEN)
nginx 1901 nginx 26u IPv4 41081 0t0 TCP domain:https->20.235.198.146.dyn.plus.net:51453 (ESTABLISHED)
nginx 1901 nginx 28u IPv4 44603 0t0 TCP domain:https->crawl-66-249-66-88.googlebot.com:45791 (ESTABLISHED)
I’ve replace my URL with domain to get round the early poster URL restrictions
Is this because I’ve got nginx running on the domain?