Sangoma S700 and Endpoint Manager

We purchased a Sangoma S700 with expansion module for our switchboard operator. I am trying to get it setup in the Commercial Endpoint Manager with the setup she was used to before. She was using an Aastra 6739i. Before we had some line keys setup to transfer to a direct extension but when I choose transfer for the S700 in Endpoint Manager, the value goes away so I am unable to put in the extension to transfer too. Is there another way of doing this?

You want a BLF button.