You need yo solders the headers to the pcb, six cables: 2 for power (VCC and GND) and four for control the stepper motor. I put small capacitor in the power connector of the ESP32-CAM.

I presented the engine in the 3D model, a mark where the screws will be. Then use the drill to make the holes.

Be sure to run the wires through the 3d piece before crimping the connectors.

From the usb pcb you have to have two power cables, VCC / GND for the ULN2003, and VCC / GND for the ESP32-CAM.