Picar-x Robot Hat and robot arm

The pic carX robot hat has extra PWM pins ( i think 3) . Can one use these pins to control the robot arm?
I am looking at reusing the pi carx robot-hat board to control the robot arm.

You can, but you need some code programming skills, because you need to modify the code.

coding is fine with me. Any pointer to code or docs would be helpful.
Also whats the process to buy the robot arm without the board?

You can refer to the git code for picar-x, robotic arm:

I don’t know if this is the right product for you: