Turn a light bulb on/off with SNZB-01 zigbee switch on Node Red Ihost

Hi, (i’m french and i use google translate)
I’m looking to turn on a sonoff wifi connected bulb with Node Red (to learn how to use it) with a sonoff SNZB-01 zigbee button.
I put a first Event block where I select the button, but afterwards I can’t create a toggle switch system. When I click on the button, if the light is on then I turn it off and vice versa. I’m completely stuck on this simple thing. Isn’t there an if function with multiple inputs? THANKS ! (I don’t know javascript but I’m going to try it)