By careful reading and re-reading I am understanding that I don’t have to use Nginx for Nextcloud Snap. Overkill. I already have Nginx for some small websites on the same Raspberry Pi, but even then I do not need Nginx for Nextcloud Snap. Just have Nginx not respond to requests for my new ‘cloud’ domain name, so that Nextcloud Snap Apache can do that.
So I reversed the port 82 setting of Nextcloud back to the original ports 80+443, and follow instructions from: Managing HTTP encryption (HTTPS) · nextcloud-snap/nextcloud-snap Wiki · GitHub
I am getting a problem there too, but thats not the topic of this question. I guess this topic can be closed. I posted the new problem as: Unexpected error DistributionNotFound: The zope.interface