Hello Spela !
My name is Eleanor and I'm pretty good at using construct 3,
If you want to do that, make your function have a return value and create a local variable,
and then in your action so "add to variable: functions.function(...args)"
and you will get the result that you want.
— Unfortunately, to use a function expression as a part of a condition, it can't be set to type None. It was possible in C2, but not anymore.