You need to install the Aspera Connect plugin before uploading your files. If you dont have Aspera Connect plugin installed in your computer, please Download Aspera Connectand install it first.
[path/to/ascp]: Microsoft Windows: C:\Program Files\Aspera\Aspera Connect\bin\ascp.exe or
c:\users\[username]\AppData\Local\Programs\Aspera\Aspera Connect\bin\ascp.exe
Mac OS X: /Applications/Aspera/Connect.app/Contents/Resources/ascp (for admin's installation) or
/Users/[username]/Applications/Aspera/Connect.app/Contents/Resources/ascp (for non-admin's installation)
Linux: /opt/aspera/bin/ascp or
/home/[username]/aspera/connect/bin/ascp
[path/to/key/file] must be an absolute path, e.g.: /home/keys/aspera.openssh
[path/to/folder/containing/files] needs to specify the local folder that contains all the files to upload.