Mysteries of locks

A few days ago, the electronic door keypad I ordered, arrived. Thus I set to today to make the thing work. Programming it was straightforward enough and I could get the light to turn green from red.

 First the light was red..

Then the light was green...

As you can see, I connected the keypad to a 12v battery. I connected a 12v buzzer (bottom right) and tried to make the buzzer buzz. It didn't so maybe I'll have to rethink my reading of the instructions, the salient point of which is here.

It looks as though I should connect the blue wire to the buzzer and the buzzers other wire to the negative. I did that and nothing happened. That has me just a little flummoxed.