2 brushless ESCs on flysky-i6x
 

Hey,
​​​​​​I have a 3D printed hovercraft I'm assembling, everything is working so far but I am at the point of wanting to test it. I have two brushless motors connected to ESC's and am using a Flysky-i6X transmitter. I would like to control the speed of the motors independently, the thrust motor already working off of the throttle control. I have seen this done before (in the video I got the idea from) but they were using a different transmitter. The I6X has two dials one of which would be perfect for what I need but I am unsure how to set it up and am unable to find any instructions anywhere.
Does anyone know how to set this up or have any links to somewhere I can find answers.
I am very new to this so I may just be missing something obvious.
Cheers