Since SSH login is disabled on the server, you cannot navigate the file structure without an ftp client. But there is an alternative SCP
scp -i pathToMyKeyFile -r sftp.syncore.se:. {local path}
This will copy the whole file structure from the server to {local path} on your computer. If you wish to transfer a file to the server, use the following command:
scp -i pathToMyKeyFile {local file} sftp.syncore.se:files/upload/{filename on server}
and if you want to upload a complete directory with files:
scp -i pathToMyKeyFile -r {local directory} sftp.syncore.se:files/upload/{directory name on server}
Alternatives
There are some ftp clients for Linux that can authenticate using keyfiles. But instructions for using different Linux clients lies outside of the scope of this instruction page. you can contact
sftp@syncore.se if you need assistance with a particular client.