I've spent a day trying to set up a surface with an oscillating Opacity but I cannot figure out how to connect the oscillator and the opacity value. Here is how far I got:

But nothing is happening despite the oscillator value moving up and down. I got the OSC address by right clicking the oscillator and clicking "copy OSC address". Pressing learn just brings up a "waiting for event" popup that doesn't seem to do anything.
Any idea of how I can use the oscillator to control aspects of my map?
Thanks!