Manual mode do not drive straight Rover 4.0

Hi, everyone,

I have a rover with two motors and two ESC (Servo1_Function 73 and Servo3_Function 74
, in manual mode it does not drive straight ahead but pulls to the right.
In automatic mode it drives very straight.

What is the correct procedure to properly trim the engines?
I didn’t get a good result via the remote control or via Servo1_max.

I found the following ->

But I don’t know if and how I should adjust it. Many thanks for your help.
Hardware is a Pxhawk 2.1 cube Purple or Pixhawk 2.4,8 and Rover version 3.5.2 and 4.0

Many Thanks .