You can backup your opnsense configurations locally, or in google drive, or in Nextcloud.

To use Nextcloud, a Nextcloud server must be installed and accessible via opnsense. As opnsense works as router and dhcp server, and the nextcloud server is behind this router, so naturally, the nextcloud is accessible.

• Install the os-nextcloud-backup plugin
• On Configuration->Backups enable Nextcloud and make the settings

• Under System->Settings->Cron make a cronjob to to the backups