Low input level when trying to calibrate Apogee Quartet

[Slopdrop]

I am trying to calibrate my Apogee Quartet. When I try to match the input volume to the output volume, it will only output as high as -56.55 (or so) dbFS with the Quartet input turned up as high as possible.
Hoping someone may know why this is and how to fix.
M1 Mac Mini
Latest ver Big Sur
REW ver: 5.2

ok. I figured it out. The input had to be set to instrument.