What is the best way to convert a cassette tape to digital?

it is not a computer it is like this one but with a thunderbolt 2 connector were the usb connector is
https://www.amazon.com.au/Blackmagic-Design-Intensity-Shuttle-Bintsshu/dp/B003WSQTWU
and my computer is not recognizing it as being connected i need something that will go from tape deck to the computer that works