Define Output (W)

May be I am overthinking about this and therefore not sure about how to set this.
I have set my inputs as following where I have one VT and the 3 incoming phases (Main_) plus the 3 output phases from the inverter (Inv_).:

How do I define an output to calculate the power of any of the above inputs? I mean what do I input in an output like “Pow_Main_R” ?

Should I simply input Main_R and the device will calculate the power for such phase?
Thanks for helping

You can see the current power in the status display. You can read about outputs in the docs.