Letsencrypt can't

I’m trying to set up nextcloud pi. it seems ok on local network, but no https. ncp-config > Networking > letsencrypt says:
Plugins selected: Authenticator webroot, Installer None
Unable to register an account with ACME server

FYI ports 80 & 443 are forwarded and as far as I can tell my domain is working.

Also, this is a replacement NC setup on a Pi4. Old one ran on a laptop.

Any ideas folks?

Forgot to provide a valid email account, maybe?
Not enough info, I’d run and look at output of ncp-report and ncp.log, if email does’nt do the trick.