SAN DISK PORTABLE SSD NOT SHOWING AS DEVICE ON REKORBOX

Hello how are you! Im having an issue, When I plug In my new SAN DISK EXTREME PORTABLE SSD DEVICE 550 GB is not showing on my REKORDBOX account. So I can't export my music to the device. Any ideas on how to make it appear as a device?? Normally I use USBS and they all appers the second I plug them to the USB port on a Mac. 

Kind Regards 

Sergio Beats