Setting up an Aux send on GLD112

I am trying to create an Aux send for our induction loop system. Any advice would be helpful!

RTFM

look for the (most likely predefined auxes) on the right Hand side of the mixer)
press the “mix” key of the aux
now all the channelfaders send Signal to this aux when pushed up

(define the Output of the aux in the I/O menu)