Failed To Remove Backups Stored Locally On My Server

I need help, please. This plugin works but failed to remove the backups stored locally on my server after transporting them to Google Drive.

I turned on this under Expert settings;

Delete local backup:
Check this to delete any superfluous backup files from your server after the backup run finishes (i.e. if you uncheck, then any files despatched remotely will also remain locally, and any files being kept locally will not be subject to the retention limits).