Where is Screenly OSE stored via Docker?

I switched my Screenly OSE install from native on Raspbian to balena deploy and I have a question:

Where is the docker container with instance files? In the past, when I generate a backup to download, after downloading the Screenly backup still sits in the static subdirectory and takes up a lot of space. I’m used to just WinSCPing in and deleting it after I download it. It would also be good to know where this is for maintenance of other sorts.

Thank you!