Access folder / file within directory outside config folder

Hello together,

I would not consider me a total newbie with coding and home automation, but I now hit a roadblock and can not find any hint how to resolve it online:

Running a Raspberry Pi 4B with the standard HAOS installation. Config files are stored in the folder /homeassistant and native local backups are created in the folder /backup

Triggering a shell command I was able to create a file in the /homeassistant folder and also transfer this file externally to another remote FTP server.

However I can not get access from this shell command to anything in the /backup folder - neither create the same file in this location nor transfer files from that folder locally or remotely.

Can somebody point me please into the right direction, how to access the /backup folder from within any automation? I assume it has to do with HA running within a container? And potentially thus with a user not being able to access the other folder(s)?

Thanks for any explanation or hints how to work my way around :slight_smile: