If I recall right you have an EQ6 mount so you should get one of these to connect the laptop straight to the mount.
https://www.bintel.com.au/product/sh...eq6-interface/.
Note that you can get standard USB-serial cables that look the same and cost less but operate at a different voltage and could damage your mount if you connect them to it directly. They will work if you connect them to the hand controller instead.
Alternatively, for now you could connect the guide camera to the mount with a ST4 cable but that would only allow guiding but not goto control from the laptop.