http://mponpsecu5qaqu4s7chzbldsp6hu45pwecvr72m26xbf6lo3slqo6tad.onion/docs/INSTALL.html
Most FTP clients list permissions in the form of User (Read, Write, Execute), Group (Read, Write, Execute) and Other (Read, Write, Execute). You need to tick all of these boxes to set correct permissions. On Windows systems, you need to ensure the directory is not write-protected and that it has global write permissions (see your server's documentation or contact your hosting provider if you are unsure on how to achieve this).