3D FlipBook - Clean up files

It looks like the plug-in has created thousands of files with the extension bk and others, for example group-name-10346-1416x2048.bk.png At the moment we're trying to migrate our server to another location, but it's 13 GB and it's impossible. We've noticed that there are many files generated by the plugin, but we're not sure which ones to remove. Can we remove the .bk files? Would it be possible for you to have a cleanup tool? As otherwise, we can't migrate our website due to the thousands of files that are generated. We estimate that our server has only 900 MB but we are getting around 13GB with the files generated.

Erich.