can't dub using channel 2

I now have Tascam - 144mkll. I can only record on channel 1. I’m using my guitar and have the switch setto guitar on channel 2 but it will not record. I can hear it but it won’t record. What am I doing wrong?

You need to connect your device ports to the Cubase busses in VST connections, and then select the correct input bus for the track you want to record to…
Explained in more detail in the manual “audio recording specifics”, or “setting up your system”…