How do I get the pwm working on the Poe shield fan?

I have a couple sweet potatoes and when the poe+pwm shield is on and the fan is plugged in, it just screams at max speed all day on both units. How do I get this working properly, and why isn’t it documented somewhere? When I emailed they asked me to make a forum post instead of answering the question

Edit: it’s the loverpi active media center case for USB C, which didn’t even come with documentation on where to land the leads either.