… that’s what is recommended! so you need DNS including some human readable “domain” name connected to your public IPv4 and the server should be publicly available. Nextcloud is a sharing and collaboration service. any publicly available service should have a valid SSL certificate and encrypted on https://cloud.yourdomain.tld
the links posted above are in sequence so that you can read them like a manual. and no, if you’ve read the documentation you’ll see that the snap is a community project with own documentation… which is why it was linked above. see Installation on Linux — Nextcloud latest Administration Manual latest documentation
Installing via Snap packages
Nextcloud snap is a community driven installation method and is designed to be easy to install and simple to maintain. The ideal Nextcloud snap is an “install and forget” Nextcloud instance that works on most architectures and updates itself without needing administrative skills. Combining Nextcloud with snapd makes it a perfect fit for IoT or scalable environments. Snapd is a secure and robust technology which the Nextcloud snap team has embraced.
Most importantly snaps are designed to be secure, sandboxed, containerized applications isolated from the underlying system and from other applications.
maybe this will shed some light: