Thank you, problem solved!
I just copy pasted this line -> {combos = {{key = "JOY_BTN6"}}, down = iCommandPlaneTrimOn, up = iCommandPlaneTrimOff, name = "Trimmer", category = "Ins Cyclic Stick"}, in lua joystick file
and it bound the button6 to the Trimmer row with T key. Everything works, thank you.