Where are the backups in the file system hierachy? Can't connect via browser interface

After the last core update, my HA installation seems to have become inaccessible from my LAN. I have HASSOS running on an RPi4. I’m looking to access the backups on the SSD from which I boot, so that I can install and then restore from a backup (which I always request before updating).

I can access the file system by plugging the SSD into my desktop. I see three ‘drives’/partitions on the SSD:
hassos-boot
hassos-overlay
hassos-data

Please could someone advise the file name conventions for the backup files and also their location within the file system?

Edit: A little extra information. The RPi4 is getting the designated IP address from my network and is accessing the internet (it updates itself on duckdns.org), so I know it’s booting, but when I try to access the IP address using the static IP my LAN gives it, which is the same as my router is reporting) and the port address I always get a time out. I have tried accessing using Firefox, and Edge browsers, and get the same timeout.

Many thanks.

I believe they should be in “/mnt/data/supervisor/backup” on the data partition.