[ROS | Ridgeback] How can I convert the wheels to 3 PPR /joint_states?

my original ridgeback is made up of 4 wheels joint and move by /cmd_vel.
Also in RViz it moves by mecaum_drive_controller even it doesn’t provide mecanum wheel angle.
How can I convert the wheels to 3 PPR /joint_states?
Cause NVIDIA ridgeback works with 3PPR joints

I’ve tried underlying graph but doesn’t work.

Have no idea where to start :P…