Backupery for Slack produces a zip archive that may be uploaded back to Slack if necessary. The archive is placed into the ReadyToImport directory:
To import the archive into Slack you’ll need to use the Slack import tool. After successfully importing the data you may notice that the file uploads are not imported properly. Namely, if you try to download any of the files, you’ll get a wrong file.
The cause of the problem is that Slack requires the archive to have so-called “File Download Token” inside. The token is generated only if you run the export manually using Slack Export Tools:
Currently, it’s not possible to generate the token automatically on behalf of any third-party application.
However, we’re currently working on workarounds we can provide for you if you need to import the files. Please contact us and we’ll be happy to discuss all the possible ways to import the files.