That is configured in Options->CAN Bus->CAN input channels. If you configure it by hand you need to click the View/Hide all fields.

You will need to know the format of the CAN data (address, bit positions, multiplication factor, big/little endian), which is given by the documentation of the unit you connect to.

Sorry I wasnt clear, 

The canbus configuration is ok.

So when I add the field in can input settings, then the new value appear in the gear ratio setup and I can select it but I get this error

Plugin not installed or configured

I don't understand fully. Give me a call on +47 4840 1279 (whatsapp or phone) and I will take a look. Install Ultraviewer first so I can login to your PC.