These are the instructions for line-command FTP. On the same page, scroll up to read about how to use an FTP client. https://galaxyproject.org/ftp-upload/#upload-with-lftp-command-line
Of note: the server name
ftp://usegalaxy.org would never be used. The target server name for a client is
usegalaxy.org. For Lftp, it is either
ftps://usegalaxy.org depending on how you are connecting.
If problems continue after doing this, then check to see if any firewalls are a factor. This could involve: contacting your local admin, adjusting firewall settings on your computer, and/or contacting your ISP provider.
Hope that helps! Jen, Galaxy team