First, go to Panels - VST Inputs and make active all inputs.

Then, go to Panels - VST Channel Mixer, and on the top of each channel where it says IN 1 L, IN 1 R, change them to the appropriate inputs of your interface by holding CTRL on your keyboard and clicking the button.

Go to Options - Multirecord - Active and select active. Once it is checked a new column appears to the left of the track name labeled R (record enable). Arm the tracks for recording and push record in your transport.