So, the script I have is just this:

    sudo -u abc php /data/www/nextcloud/updater/updater.phar --no-interaction

Although, it looks like I need to add this also:

    occ db:add-missing-indices

And, I thought I had it in my crontab, but now I don't see the job there. I haven't touched it in months, and I'm on the latest version of nextcloud, so presumably it's still working. But I honestly can't remember how I set it up.