Acro Trainer Mode on RC6

Hello there!

Its my first Post here so excuse me if I made something wrong.
I have a Spektrum DX6 Radio and I want to train in Acro Mode on my first Quadcopter Build with a Pixhawk. In the Settings I can only switch the Trainer Mode for Arco on Channel 7/8.
Is it possible to switch it on Channel 6?