Modifying recently purchased cnc and want to modify to control through UCCNC

Hello! I am getting back into routing and I am looking for a little guidance. I recently purchased a cnc router, that runs manually. However, I want to set it up that I can turn on the spindle via the software (UCCNC) and have the G-Code specify the RPM (Aspire). Here is the current setup and I am curious what I need.


Software (UCCNC V1.2111)

To Breakout Board (UC400ETH)

Breakout board (ST-V3)

X Stepper drive & Stepper Motor

A Stepper Drive & Stepper Motor (X-Slave)

Y Stepper Drive & Stepper Motor

Z Stepper Drive & Stepper Motor

Huanyang 220V 4.0KW FVD & Spindle (Not Sure which model)

Now, the ST-V3 has a relay to control a vfd/spindle. However, as I am wiring it up, I believe I need a PWM board, but not sure how this is implemented in my current setup. I imagine it is controlled via my VFD and breakout board, where the breakout board will send the signal and the PWM board will continue that signal to the VFD. Any help on this is appreciated and please go slow. I'm still learning.