Easiest complete backup of self-hosted Retool?

I'm a self-hosted non-developer and the hardest thing to get my head around has been Docker, not Retool. We're running and stable - knock on wood - but if we had serious trouble with the containers we'd be up-a-creek. There is zero Docker expertise in-house. We're excellent at Google (that's how we got this far), but at this points searches are turning up documentation that is written for the distributer (Retool) and not the user (me.)

All that said, it's time to update our on-prem instance to the latest version and I'm stuck on the backup procedures found here. We don't use a cloud platform or Git Synching, and don't manage our DB outside of Retool. I'd be satisfied with just making copies of the essential directories and "restoring" them if the update goes sideways, but I'm worried this will leave something unaccounted for.

Is anyone here in a similar situation? How do you manage and protect your self-hosted Retool?

Thanks in advance.