This is not completely what you are after, but might get you on the way, if you are running a local version of emoncms and using a browser to interact. I’m not sure if you are familiar with linux command line - but it’s quite straightforward. You need to be able to ssh into your server to do it.
There is an emoncms-export.sh script which can be manually run from the Backup tab on the emoncms. On my sytstem (low-write 10.2.6) it is located in /opt/emoncms/modules/backup. This exports all the data as described in the Export tab of the Backup page. You can change the backup locations etc if you want by editing this file.
You can run an automated backup using cron (type crontab -e on the command line). For example, I run this script at 11:15 pm each night by adding this line into my crontab:
15 23 * * * /opt/emoncms/modules/backup/emoncms-export.sh
Of course this will accumulate backups unless you manually delete them, but it is easy to setup another cron job to just delete old backups. This command will find and delete backups (actually any files with a .gz extension in this case) that are older than 8 days (the +8)
find /var/opt/emoncms/backup/ -name '*.gz' -type f -mtime +8 -exec rm -f {} \;
To run this in cron, put it into a text file named like delete_backups.sh and make give it permission to run (chmod a+x delete_backups.sh).
If you aren’t familiar with cron check out https://crontab.guru/, where you can easily confirm if your schedule entries do what you expect.
This approach only backs up locally, so if you lose your SD drive you will also lose the backups. I use a remote unix backup server called rsync.net (about $US10/month for 400 GB storage - for all my backups, not just emoncms). This uses a similar cron approach, and backs up from my emon rpi every day. If you are interested I can post the rsync command - it’s very simple actually.
I run node-red on a different rpi, and backup this up using the same approach. All auto, just an occasional check to make sure all is being backed up as expected.