How to use single click/tap plus modifier (function key) on trackpad?

I'd like to have middle-click by holding the function key and single-tapping or clicking on the trackpad. But I can't find anything like "1 finger tap" or "1 finger click" to choose as the trackpad gesture. Is it possible?

Anybody? I found https://middleclick.app/ which does middle-click by function-click. Is there no way to do the same thing with BetterTouchTool?