Any breakount board will work, even one of these cheap ones. All 4 motors drives connect to it.
5-Axis CNC Interface Adapter Breakout Board For Stepper Motor Driver Mach3 USB
Just plug the cable into port 2 or 3 on the UC300 motherboard. Here's how to wire it.
https://www.machsupport.com/forum/in...html#msg199107