Backing up and restoring message attachments is only availabel to premium users.
When backing up and restoring message attachments there are some limitations enforced by Discord. This is because Xenon can't actually store the files, it only stores a link to each attachment.
Message attachments include any images, videos, or other files that are sent in a Discord message.
If you are looking for a solution that actually stores the message attachments and can restore them even if the backup is older than 24 hours or the original messages have been deleted, please check out Xenon Vault.