Nextcloud is installed from upstream (i.e. direct from Nextcloud - not a Debian package) so you can't use apt to upgrade it. There isn't any functionality within Webmin either, so you can't use that.
However, if you follow the instructions as noted in the Nextcloud upgrade docs then that should work! :)
A couple of notes though. If you are using v16.1, then you can use the 'turnkey-occ <command>' command (rather than using 'sudo -u www-data php occ <command>'. If you'd rather just use the commands exactly as they are in the Nextcloud docs, then install 'sudo', like this:
apt update && apt install -y sudo
I encourage you to be sure you have a backup (of some sort) before you start, just in case something goes wrong. Ideally test that your backup works before you start as well.
If you have any further questions or concerns, please ask. If you hit any hurdles, please share as much info as possible, including sharing any error messages you get.
Neither apt, nor Webmin - Follow the Nextcloud docs
Nextcloud is installed from upstream (i.e. direct from Nextcloud - not a Debian package) so you can't use apt to upgrade it. There isn't any functionality within Webmin either, so you can't use that.
However, if you follow the instructions as noted in the Nextcloud upgrade docs then that should work! :)
A couple of notes though. If you are using v16.1, then you can use the 'turnkey-occ <command>' command (rather than using 'sudo -u www-data php occ <command>'. If you'd rather just use the commands exactly as they are in the Nextcloud docs, then install 'sudo', like this:
I encourage you to be sure you have a backup (of some sort) before you start, just in case something goes wrong. Ideally test that your backup works before you start as well.
If you have any further questions or concerns, please ask. If you hit any hurdles, please share as much info as possible, including sharing any error messages you get.