Pico RGB Keypad - APA102 CS handling

I was wondering if you could share the portion of the schematic for the Pico RGB Keypad that shows how you implemented a CS signal for the APA102 leds (since they don’t actually have a CS pin/signal).
The implementation on the Pico RGB keypad works great and I would like to be able to use this for other projects that use the APA102 leds.

Martin Z.