In order to enable SSH you will need to install a supplementary SSH enablement package available for download from the link below. I am going to assume that you are not using Wavelink Avalanche for MDM so you will want to grab the ActiveSync version of the installer. The exe will install a client on your PC which you can then use to push the SSH support to the individual devices. Alternatively you can pull the SSH Cab from the Install Folder for the SSH ActiveSync installer and then manually copy and run that directly on the devices.
As far as the licensing goes you will have to reach out to your hardware vendor to determine if they also sell Wavelink licensing, or you could reach out to Wavelink Technical Support directly. I don't think you will be able to purchase licensing through the support forums.