SSH access is needed to interact with the Klipper configuration system. You will specifically need to SSH into your printer to add Klipper extensions.
To log into your printer, first detrmine it's IP address from the front panel's network tab.
Then open a shell (or Terminal on Windows) and type:
ssh mks@x.x.x.x
Where x.x.x.x is the IP address.
The password is makerbase