They offer 1 TB of Free space.I would like to use that space via command line.
They’re based on ownCloud and all communication goes over WebDAV. Support for it (WebDAV) is planned (https://github.com/ncw/rclone/issues/580). Having said that there are lot’s of (CLI) tools available that support WebDAV and/or ownCloud. I use Duplicity for my daily (encrypted) backups with STACK as backend for example.