Rover mixing chanels throw QGC and joystic inputs

Hello community! I have a question regarding mixing of chanel inside my qgroundcontrol. For now, i’m using Steamdeck inputs to control my rover (use only 2 chanels) for now. Previously, I used radiomaster tx12 where I mixed it to create something like “tank turn”. Can i do the similar from the QGC for my joystick output? Thanks!