How to increase counter value for when you have entered a trigger volume?

Hi guys! I guess I arrive to this a too late but I have a question about it.

i also want to make the counter (instead of with a triggerbox it will work with a button click). My question is: how did you build everything that it’s set after the “Cast to player” node in the first image.

I mean, I don’t know how to tell it to increase the variable by one every time I press my button.

Thanks in advance!!!