Map F1 key on WASD keyboard to the F1 (lower brightness) on Mac BT keyboard

I've been using the Apple Bluetooth keyboard with built in funciton keys. I'd like to map, for example, F1 on my WASD keyboard to the Brightness Down function (F1) as done on the Apple Keyboard. Feeling like a clueless user here. Maybe I'm pressured by work's deadlines. Thanks in advance for any guidance.

I figured this out. The columnar view of BTT threw me for a loop. I expected the columnar view to work like Finder column-view but, rather, BTT uses the far right column as a property view.

Once I added an action all was good.