I’m new to the forums.
I’m using the Pirate audio 3W amp  in a project with a RasPi 3a+ but i’m finding that i need access to a couple of gpio pins. Not specific ones - any will do, and I don’t need any of the special-purpose pins (I2C, serial, etc.). I was thinking of making a simple breakout board out of a bit of perfboard and a stacking header connector so that i can access them.
Can anyone tell me which pins the amplifier hat uses and/or which are unused and free?