Could it be possible to recieve the mix of FOH on QC

Could it be possible to recieve the mix of FOH on QC, and listen to it thru the headphone out?

Yes.
Example: Connect the plugs of the FOH mix to the returns 1/2, create a empty row, patch the input of this row to returns 1/2 and the output to out 3/4. With the internal headphone mixer you can mix all outputs as desired, e.g. mix your guitar sound to the FOH mix.
However, I only have the manual, it is not described in detail, but that’s how it could work.

Thanks. for the info.