i have active studio monitors .. going into a small behringer zenyx mixer .. so the studio monitor are conected in the main output of the mixer ..

i need to connect a pedal call a cabinet simulator to it and my line 6 uber metal so i can hear the sound .

so how do i connect a pedal ( the cabinet simulator ) who has 1 output .. to the mixer who seem to have both a left and right input ??
Bedroom rock star :

- Gibson Les paul Standard 2001 Honeyburst .
- Agile 3200 Slim
put it in the left or (mono input)
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate