As it is, there's no way to actually write to a save file, as the default launcher only gives the application read-only access to the filesystem. This attempts to fix that.
Keep in mind that I have no idea how flatpaks work or anything, so I'm not really sure if this is a proper fix. Manually running the application from the command line with --filesystem=host:rw added fixes the problem, so I'm inclined to believe it is.
As it is, there's no way to actually write to a save file, as the default launcher only gives the application read-only access to the filesystem. This attempts to fix that.
Keep in mind that I have no idea how flatpaks work or anything, so I'm not really sure if this is a proper fix. Manually running the application from the command line with
--filesystem=host:rwadded fixes the problem, so I'm inclined to believe it is.